Week 19 Lump In The Leg EXAMINATION OF THE LOWER LIMB 1. Discuss the clinical problem of lumps about the knee (including the differential diagnosis). Differential diagnosis Faulty development. Injury: Fracture. Fracture callus. Inflammation: Cutaneous abscess. Boil. Carbuncle. Lymph node enlargement. Rheumatoid nodule. Sebaceous cyst. Tumor: Malignant. Osteosarcoma. Chondrosarcoma. Adamantinoma. Malignant fibrous histiocytoma. Leiomyosarcoma (smooth muscle). Liposarcoma. Benign. Osteoid osteoma. Osteoblastoma. Osteochondroma. Chrondroma. Chondroblastoma. Chrondromyxoid fibroma. Fibrous histiocytoma. Lipoma. Lymph node enlargement. Clinical problem Loss of function. Systemic infection. Metastases. Pathological fracture. Pain. 2. Perform an examination of a bony or soft tissue lump in an extremity to establish a likely diagnosis. History How long has it been there? Does it hurt? Any other lumps? Is it getting bigger? Ever been abroad? Otherwise well? Physical examination Six S’s: Site. Size. Shape. Smoothness. Surface. Surroundings. Also: Consistency. Tenderness. Multiplicity. Does it transilluminate? Dark room. Bright, thin, pencil torch. Shine light through the lump towards your eye. If it glows red it is said to transilluminate. Fluid filled lumps are transilluminable swellings. Is it fluctuant? Place one forefinger (the “watch” finger) halfway between the periphery and the centre of the lump. Place the forefinger of the other hand (the “displacing” finger) diagonally opposite the first at an equal distance from the centre of the lump. Press with the displacing finger and keep the “watch” finger still. If the lump contains fluid, the “watching” finger will be displaced in both axes of the lump. Is it fixed to skin or underlying structures? Lumps in certain sites call to mind particular pathologies. Remember to feel if a lump is pulsatile. 3. Revise the anatomy of the thigh, knee and popliteal fossa (including adjacent neurovascular structures). Femur Upper end: Head: fovea capitis. Neck: 125 degrees to the long axis of the shaft. Greater and lesser trochanters: intertrochanteric line anteriorly, intertrochanteric crest posteriorly. Shaft: Linea aspera: divides below into medial supracondylar ridge (continues as adductor tubercle) and lateral supracondylar ridge. Popliteal surface: flat triangular area on posterior surface of distal shaft. Gluteal tuberosity: posterior surface below greater trochanter. Lower end: Lateral and medial condyles: separated posteriorly by the intercondylar notch. Medial and lateral epicondyles: adductor tubercle is continuous with the medial epicondyle. Skin of the thigh (front and medial) Femoral branch of the genitofemoral nerve: L1. Lumbar plexus. Skin of the intermediate area in the inguinal region. Ilioinguinal nerve: L1. Lumbar plexus. Skin of the medial area in the inguinal region. Lateral cutaneous nerve of the thigh: L2, 3. Lumbar plexus. Skin of the lateral aspect of the thigh and knee and of the lower lateral quadrant of the buttock. Intermediate cutaneous nerve of the thigh: L2, 3. Femoral. Skin of the anterior aspect of the thigh. Medial cutaneous nerve of the thigh: L2, 3. Femoral. Skin of the medial aspect of the thigh. Obturator nerve: L2, 3, 4. Skin on the medial aspect of the thigh. Patellar plexus: Lies in front of the knee. Formed by terminal branches of the lateral, intermediate and medial cutaneous nerves of the thigh and the infrapatellar branch of the saphenous nerve (L3, 4). Anterior fascial compartment Muscles: Sartorius: Immediately below ant sup iliac spine. Upper med surface of shaft of tibia. Flexes, abducts, lat rotates thigh at hip. Flexes, med rotates leg at knee. Ant div of femoral N (L2, 3). Iliacus: Iliac fossa within the abdomen. Lowermost surface of lesser trochanter of femur. Flexes hip. Femoral N in abdomen (L2, 3). Psoas major: Transverse processes of L1-5, bodies of T12-L5 and intervertebral discs below bodies of T12-L4. Middle surface of lesser trochanter of femur. Flexes hip. Ant primary rami of L1, 2. Pectineus: Pectineal line of pubis and narrow area of sup pubic ramus below it. A vertical line between spiral line and gluteal crest below lesser trochanter of femur. Flexes and adducts hip. Ant div of femoral N (L2, 3). Occasional twig from obturator N (ant div-L2, 3). Quadratus femoris: Lat border of ischial tuberosity. Quadrate tubercle of femur and a vertical line below this to the level of lesser trochanter. Lat rotates and stabilizes hip. N to quadratus femoris (L4, 5, S1). Blood supply: Femoral artery. Nerve supply: Femoral nerve. Medial fascial compartment Muscles: Gracilis: Outer surface of ischiopubic ramus. Upper med shaft of tibia behind sartorius. Adducts hip. Flexes knee and med rotates flexed knee. Ant div of obturator N (L2, 3). Adductor longus: Body of pubis inf and med to pubic tubercle. Lower two-thirds of med linea aspera. Adducts hip. Ant div of obturator N (L2, 3, 4). Adductor brevis: Inf ramus and body of pubis. Upper third of linea aspera. Adducts hip. Ant div of obturator N (L2, 3). Adductor magnus: Adductor portion: ischiopubic ramus. Hamstring portion: lower outer quadrant of post surface of ischial tuberosity. Adductor portion: lower gluteal line and linea aspera. Hamstring portion: adductor tubercle. Adductor portion: adducts hip. Hamstring portion: extends hip. Adductor portion: post div of obturator N (L2, 3, 4). Hamstring portion: tibial portion of sciatic (L4). Obturator externus: Outer obturator membrane, rim of pubis and ischium bordering it. Trochanteric fossa on med surface of greater trochanter. Lat rotates hip. Post div of obturator N (L3, 4). Blood supply: Profunda femoris artery. Obturator artery. Nerve supply: Obturator nerve. Skin of the thigh (posterior) Posterior cutaneous nerve of the thigh: S1, 2, 3. Sacral plexus. Skin on the back of the thigh and the upper part of the leg. Posterior fascial compartment Muscles: Biceps femoris: Long head: upper inner quadrant of post surface of ischial tuberosity. Short head: middle third of linea aspera, lat supracondylar ridge of femur. Styloid process of head of fibula, lat collateral lig and lat tibial condyle. Flexes and lat rotates knee. Long head extends hip. Long head: tibial portion of sciatic N. Short head: common peroneal portion of sciatic N (both L5, S1, 2). Semitendinosus: Upper inner quadrant of post surface of ischial tuberosity. Upper med shaft of tibia behind gracilis. Flexes and med rotates knee. Extends hip. Tibial portion of sciatic N (L5, S1, 2). Semimembranosus: Upper outer quadrant of post surface of ischial tuberosity. Med condyle of tibia below articular margin, fascia over popliteus and oblique popliteal lig. Flexes and med rotates knee. Extends hip. Tibial portion of sciatic N (L5, S1, 2). Adductor magnus: Adductor portion: ischiopubic ramus. Hamstring portion: lower outer quadrant of post surface of ischial tuberosity. Adductor portion: lower gluteal line and linea aspera. Hamstring portion: adductor tubercle. Adductor portion: adducts hip. Hamstring portion: extends hip. Adductor portion: post div of obturator N (L2, 3, 4). Hamstring portion: tibial portion of sciatic (L4). Blood supply: Profunda femoris artery. Nerve supply: Sciatic nerve. Tibia Upper end: Lateral and medial condyles. Anterior and posterior intercondylar areas. Intercondylar eminence. Lateral condyle possesses on its lateral surface a small circular articular facet for the head of the fibula. Shaft: Tibial tuberosity on anterior border of the upper end of the tibia. Anterior border becomes rounded and continuous with the medial malleolus. An oblique line posteriorly, the soleal line. Lower end: Medial malleolus. Wide, rough depression on lateral surface for articulation with fibula. Fibula Upper end: Styloid process. Articular surface for lateral condyle of the tibia. Shaft: Medial border gives attachment of interosseous membrane. Lower end: Lateral malleolus. Medial surface of lateral malleolus, articular facet for the lateral aspect of the talus. Femorotibial joint (knee) Classification: Synovial. Type: Modified hinge. Articulation: Femur with tibia. Notes: Menisci are incomplete discs of fibrocartilage. Popliteal fossa Site: Diamond shaped, behind knee. Borders: Sup/lat: biceps femoris. Sup/med: semitendinosus and semimembranosus. Inf/med: med. head of gastrocnemius. Inf/lat: lat. head of gastrocnemius. Floor: post distal femur, post capsule of knee and popliteus. Roof: fascia. Contains: Plantaris; popliteal art and V and brs; tibial, common peroneal, sural and sural communicating Ns; lymph nodes and fat. Short saphenous V and post femoral cutaneous N in fascia of roof. Skin of the leg (anterior) Lateral cutaneous nerve of the calf: L4, 5, S1 Common peroneal (fibular). Skin on the upper part of the anterolateral surface of the leg. Superficial peroneal nerve: L4, 5, S1. Common peroneal (fibular). Skin of the lower part of the anterolateral surface of the leg. Saphenous nerve: L3, 4. Femoral. Skin on the anteromedial surface of the leg. Anterior fascial compartment Muscles: Tibialis anterior: Upper half of lat shaft of tibia and interosseous membrane. Inferomedial aspect of med cuneiform and base of first MT. Extends and inverts foot at ankle. Holds up med longitudinal arch of foot. Deep peroneal N (L4, 5). Inversion is at subtalar and mid tarsal joints. Extensor digitorum longus: Upper two-thirds of ant shaft of fibula, interosseous membrane and sup tibiofibular jnt. Extensor expansion of lat four toes. Extends toes and extends foot at ankle. Deep peroneal N (L5, S1). Peroneus tertius: Third quarter of ant shaft of fibula. Dorsal shaft and base of fifth MT. Extends and everts foot. Deep peroneal N (L5, S1). Extensor hallucis longus: Middle half of ant shaft of fibula. Dorsal base of distal phalanx of great toe. Extends big toe and foot. Inverts foot and tightens subtalar jnts. Deep peroneal N (L5, S1). Blood supply: Anterior tibial artery. Nerve supply: Deep peroneal nerve. Lateral fascial compartment Muscles: Peroneus longus: Upper two-thirds of lat shaft of fibula, head of fibula and sup tibiofibular jnt. Plantar aspects of base of first MT and med cuneiform, passing deep to long plantar lig. Plantar flexes and everts foot. Suports lat longitudinal and transverse arches. Superficial peroneal N (L5, S1). Peroneus brevis: Lower two-thirds lat shaft of fibula. Tuberosity of base of fifth MT. Plantar flexes and everts foot. Supports lat longitudinal arch. Superficial peroneal N (L5, S1). Blood supply: Branches from the peroneal artery. Nerve supply: Superficial peroneal nerve. Skin of the leg (posterior) Posterior cutaneous nerve of the thigh: S1, 2, 3. Sacral plexus. Skin over the popliteal fossa and the upper part of the back of the leg. Lateral cutaneous nerve of the calf: L4, 5, S1. Common peroneal (fibular). Skin on the upper part of the posterolateral surface of the leg. Sural nerve: S1. Tibial. Skin on the lower part of the posterolateral surface of the leg. Saphenous nerve: L3, 4. Femoral. Skin on the posteromedial surface of the leg. Posterior fascial compartment Superficial muscles: Gastrocnemius: Lat head: post surface of lat condyle of femur and highest of three facets on lat condyle. Med head: post surface of femur above med condyle. Tendo calcaneus to middle of three facets on post aspect of calcaneus. Plantar flexes foot. Flexes knee. Tibial N (S1, 2). Main propulsive force for jumping. Plantaris: Lat supracondylar ridge of femur above lat head of gastrocnemius. Tendo calcaneus (med side, deep to gastrocnemius tendon). Plantar flexes foot and flexes knee. Tibial N (S1, 2). Soleus: Soleal line and middle third of post border of tibia and upper quarter of post shaft of fibula including neck. Tendo calcaneus to middle of three facets on post surface of calcaneus. Plantar flexes foot (aids venous return). Tibial N (S1, 2). Main propulsive force for walking and running. Deep muscles: Popliteus: Post shaft of tibia above soleal line and below tibial condyles. A facet on lat surface of lat condyle of femur postero-inferior to epicondyle. Tendon passes into capsule of knee and a few fibres attach to lat meniscus. Unlocks extended knee by lat rotation of femur on tibia. Pulls back lat meniscus. Tibial N (L4, 5, S1). Popliteus bursa lies deep to tendon. Flexor digitorum longus: Post shaft of tibia below soleal line and by broad aponeurosis from fibula. Base of distal phalanges of lat four toes. Flexes distal phalanges of lat four toes and foot at ankle. Supports Lat longitudinal arch. Tibial N (S2, 3). Flexor hallucis longus: Lower two-thirds of post fibula between median crest and post border, lower intermuscular septum and interosseous membrane. Base of distal phalanx of big toe and slips to med two tendons of flexor digitorum longus. Flexes distal phalanx of big toe, flexes foot at ankle, supports med longitudinal arch. Tibial N (S2, 3). Tibialis posterior: Upper half of post shaft of tibia and upper half of fibula between median crest and interosseous border, and interosseous membrane. Tuberosity of navicular bone and all tarsal bones (except talus) and bases of metatarsals 2-4. Plantar flexes and inverts foot. Supports med longitudinal arch of foot. Tibial N (L4, 5). Blood supply: Posterior tibial artery. Nerve supply: Tibial nerve. RADIOLOGY OF THE LOWER LIMB 1. Revise the radiology of the femur, knee and tibia in normal health. Femur Head of femur. Neck of femur. Greater trochanter. Intertrochanteric line. Lesser trochanter. Shaft of femur. Adductor tubercle. Medial epicondyle of femur. Medial condyle of femur. Intercondylar notch. Lateral condyle of femur. Lateral epicondyle of femur. Knee Patella. Distal femur. Proximal tibia and fibula. Tibia Medial condyle of tibia. Tibial tuberosity. Shaft of tibia. Intercondylar eminence. 2. Identify radiological features used in the diagnosis of benign and malignant bone lesions (include plain x-rays, CT scan, MRI scan, technetium scan). Anatomic site Spindle cell sarcomas are metaphyseal. Round cell sarcomas tend to be diaphyseal. Borders Reflects growth rate and the response of the adjacent normal bone to the tumor. Benign lesions (e.g., nonossifying fibromas and unicameral bone cytsts) have well- defined borders and a narrow transition area that is often associated with reactive sclerosis. Aggressive or benign tumors (e.g., chondroblastoma, giant cell tumor) tend to have faint borders and wide zones of transition with very little sclerosis, reflecting a faster- growing lesion. Poorly delineated or absent margins indicate an aggressive or malignant lesion. Bone destruction Three patterns of bone destruction: Geographic. Moth-eaten. Permeative. Tubular > flat bone – represent a combination of cortical and cancellous destruction. Reflect progressively accelerating growth of the underlying tumor. Matrix formation Calcification or new bone formation can produce an area of increased density within the lesion. Calcification: flocculent or stippled rings or clusters. New bone: dense sclerosis to small, irregular circumscribed masses. Both may appear in the same lesion. Neither is diagnostic of malignancy. Periosteal reaction Indicative of malignancy but not pathognomonic of a particular tumor. Malignant: noncontinuous and thin, with multiple laminations. A parallel or a perpendicular pattern may be present. Benign tumors Round, smooth, well-circumscribed borders. No cortical destruction. Generally no periosteal reaction. Malignant tumors Irregular, poorly defined margins. Evidence of bone destruction. A wide area of transition with periosteal reaction. Soft tissue extension is common. 3. Discuss the role of radiological investigation in the staging of benign and malignant tumours. This includes CT scanning of likely secondary sites of spread and nuclear medicine scanning. Tumor staging Stage IA (G1, T1, M0): low-grade intracompartmental lesion, without metastasis. State IB (G1, T2, M0): low-grade extracompartmental lesion, without metastasis. Stage IIA (G2, T1, M0): high-grade intracompartmental lesion, without metastasis. Stage IIB (G2, T2, M0): high-grade extracompartmental lesion, without metastasis. E1: tumor touches but does not elevate or penetrate the periosteum. E2: tumor elevates but does not penetrate the periosteum. E3: tumor penetrates into but not through the periosteum. E4: minimal extraperiosteal extension, not into a defined structure or space, seen as a nodule of tumor of one centimeter or less in fat just outside the periosteum, where muscle does not insert onto bone; the nodule often lies next to a small artery and may represent a small venous embolus that has destroyed the wall of the vein. E5: tumor invades any one of the following: tendon; ligament; periarticular structures (tumor is covered by synovial tissue); joint (tumor is intraarticular); muscle; bone; or space, such as the popliteal fossa or the axilla. E6: tumor invades two structures or more. Stage IIIA (G1 or G2, T1, M1): intracompartmental lesion, any grade, with metastasis. Stage IIIB (G1 or G2, T2, M1): extracompartmental lesion, any grade, with metastasis. Grade (G): G1: low grade. G2: high grade. Location (T): T1: intracompartmental. T2: extracompartmental. Lymph node involvement and metastases (M): M0: without metastases. M1: with metastases. Pre-operative evaluation Bone scans, angiography, CT, and MRI generally are not helpful in determining a diagnosis but are important in delineating the extent of local involvement. Bone scintigraphy, MRI, CT, or angiography is required to delineate local tumor extend, vascular displacement, and compartmental localization. MRI, the single best study, is most accurate for determining intraosseous extent of tumor (scintigraphy and CT are often misleading). Angiography is performed only if the primary tumor is in the vicinity of the major vascular structures. CT and MRI are equally accurate in evaluating cortical changes. MRI is superior to CT for detecting muscle involvement in the knee, pelvis, and shoulder. Bone scintigraphy Helps determine polyostotic involvement, metastatic disease, and intraosseous extension of tumor. Malignant bone tumors, although solitary, do in rare cases present with skeletal metastasis. Skip metastases are rarely detected by bone scan, since they are small and localized to the fatty marrow and do not excite a cortical response. Computer tomography Allows accurate determination of intra- and extraosseous extension of skeletal neoplasms. Accurately depicts the transverse relationship of a tumor. Study cortical bone, intramedullary space, adjacent muscles, and extraosseous soft tissue extension. Should include the entire bone and the adjacent joint. IV contrast permits identification of the adjacent large vascular structures. CT evaluation must be individualized. Magnetic resonance imaging Better contrast discrimination than in any other modality; imaging can be performed in any plane. Ideal for imaging the medullary marrow and thus for detection of the tumor and the extraosseous component. Ideal in difficult clinical situations, such as detecting small lesions, evaluating a positive bone scan when the corresponding plain radiograph is negative, determining the extent of infiltrative tumors, and detecting skip metastases. Very sensitive for evaluating the adjacent joint but may lead to overstaging if relied upon alone. Angiography Most reliable means of determining vascular anatomy and displacement. Essential to determine individual vascular patterns before resection. Thallium scintigraphy Thallium 201 accumulates in musculoskeletal neoplasms. Cannot distinguish benign from malignant tumors. Follow the response to neoadjuvant treatment and evaluating for local recurrence when MRI cannot be utilized. COMMUNICATION SKILLS 1. Revise community and professional help available to an individual and his or her family when they are dealing with a life-threatening disease. This includes ongoing support through a potentially lengthy treatment time. Psychological support Examples include: allowing the patient to express anger, fear – or any negative feeling (anger can anaesthetize pain). Conselling, e.g., with a breast cancer nurse, to prepare for mastectomy. Alternative therapy. This is one way for the patient to stay in charge and maintain autonomy. Beware of leading patients to have unrealistic hopes, but equally, it is not our place to dilute hope with cynicism. Biofeedback and relaxation therapy can reduce side-effects of chemotherapy. Cognitive and behavioral therapy reduces psychological morbidity associated with cancer treatments. Group therapy is known to reduce pain and mood disturbance, and reduce the frequency of maladaptive coping strategies. Meta-analyses have suggested that psychological support can have at least some effect on improving outcome measures such as survival. 2. Revise communications skills in clinical practice required to document a case for colleagues. Written communication Clear, unambiguous language must be used. Identify the patient (name, address and date of birth). Identify what is requested of the recipient of the message (assessment, management advice, ongoing treatment). A statement of the problem. The reason for referral. Findings from examination and laboratory investigations. Current treatment and/or management plan. Relevant psychosocial data. The patient’s insight into his or her problem and their attitude to the referral. Inadequate referral letters devalue the assistance being sought and invite retaliatory uncooperativeness. Oral communication Identify yourself by name to all the allied health professionals in your ward, clinic, operating theatre or other work environment, and ask their names in return (remember their names!). If you are unsure about their qualifications, training and experience, ask them about these (if you don’t know what their qualifications are, how can you treat them as a skilled professional?). If you are unsure what role another health professional plays in the team, ask them about this (by doing this you will make your own job easier and avoid potential embarrassment). If you would like to learn more about the role of another health professional, ask their permission to observe them at work (e.g., visit the occupational therapy or physiotherapy department). Adopt a straightforward approach to oral communication – use the telephone freely (if you are unsure of whether an allied health professional will agree with a plan of management which involves them, discuss it with them at the earliest opportunity). Don’t delay informing allied health professionals about changes in the patient’s state or changes in your thinking about the management plan for the patient if it is likely to involve them (there is nothing which irritates allied health professionals more than coming to see a patient only to find that he or she has been discharged from hospital several days earlier). Try to avoid the use of abstruse language, the only real purpose of which are to demonstrate your membership of an elite group and to exclude others from meaningful participation in clinical decision-making (beginning doctors who are unsure of their place in the team often try to impress others by using obtuse medical jargon – this generally only serves to reinforce in the minds of other doctors and allied health professionals their junior status). Participate in at least some social activities with allied health professionals and try to maintain a sense of humor. Try not to participate in denigrating (and potentially defamatory) conversations with others about allied health professionals (if you have a complaint about the performance of an allied health professional, tell them about it – if you are dissatisfied with their response, speak to the team leader or to their supervisor). 3. Discuss the process of imparting bad news to a patient or relative. Hints on breaking bad news Choose a quiet place where you will not be disturbed. This may be impossible – but at least give the matter some thought. Find out what the patient already knows or surmises (often a great deal). The picture is often confusing as surmises are not static and change rapidly, so that when you try to verify what your patient is telling you by going over the same ground again, you may get quite a different impression – both may be valid and relevant. Find out how much the person wants to know. You can be surprisingly direct about this. “Are you the sort of person who, if anything were amiss, would want to know all the details?” Share information about diagnosis, treatments, prognosis, and specifically listing supporting (e.g., nurses) and institutions (e.g., hospices). Try asking “Is there anything else you want me to explain?” Do not hesitate to go over the same ground repeatedly. “Cancer” has very negative connotations for many people. Address this, and explain that ~50% of cancers are cured in the developed world. Follow-through. The most important thing here is to leave the patient with the strong impression that, come what may, you are with him or her whatever, and that this unwritten contract will not be broken. MANAGEMENT OF MALIGNANT BONE TUMOURS 1. Discuss surgical options, chemotherapy and radiotherapy and their role in the treatment of malignant bone tumours. Surgery Most benign and many malignant tumors can be excised completely. This often necessitates wide excision and bone-grafting, or occasionally the insertion of a prosthesis. Some tumours are highly malignant with a very poor prognosis and wide excision or amputation will only be curative if metastases have not occurred. Even then recurrence is likely. Amputation may be necessary even in the presence of metastases to relieve local symptoms. Chemotherapy The use of modern cytotoxic drugs, in elaborate regimes often involving lethal doses, and using “rescue” procedures with antagonists, has greatly improved survival times for some tumors. The side effects are often severe, but the method shows great promise in the treatment of neoplasms such as osteosarcoma and Ewing’s sarcoma which were until recently almost universally lethal. Adriamycin, cisplatin, cyclophosphamide (CTX) and high dose methotrexate (HDMTX). Adjuvant chemotherapy: Microscopic metastatic disease may be eradicated if the treatment if instituted when the total boy burden of metastatic tumor is sufficiently low. Osteosarcoma is a relatively drug-resistant neoplasm, results against macroscopic osteosarcoma have been disappointing. Pre-surgical chemotherapy: Advantages: Early institution of systemic therapy against micrometastases. Reduced chance of spontaneous emergence of drug-resistant clones in micrometastases. Reduction in tumor size, increasing the chance of limb-salvage. Provides time for fabrication of customized endoprosthesis. Less chance of viable tumor being spread at the time of surgery. Individual response to chemotherapy allows selection of different risk groups. Disadvantages: High tumor burden (not optimal for first-order kinetics). Increased probability of the selection of drug-resistant cells in primary tumor, which may metastasize. Delay in definitive control of bulk disease; increased chance for systemic dssemination. Psychological trauma of retaining tumor. Risk of local tumor progression with loss of a limb-sparing option. Post-surgical chemotherapy: Advantages: Radical removal of bulk tumor decreases tumor burden and increases growth rate of residual disease, making S phase-specific agents more active and optimizing conditions for first-order kinetics. Decreased probability of selecting a drug-resistant clone in the primary tumor. Disadvantages: Delay of systemic therapy for micrometastases. No preoperative in vivo assay of cytotoxic response. Possible spread of viable tumor by surgical manipulation. Radiotherapy Some tumors are radiosensitive, e.g. Ewing’s tumor, and non-Hodgkins lymphoma of bone. In other cases radiotherapy may be used for palliation or to help union of a fracture. In general, radiation therapy is not utilized in the primary treatment of osteosarcoma. Radiation therapy is used for patients who refuse definitive surgery, require palliative treatment, or have lesions in axial locations. 2. Briefly describe the differences between limb sparing surgery and amputation. Limb sparing surgery Phases of operation: Resection of tumor: Tumor resection follows strictly the principles of oncologic surgery. Avoiding local recurrence is the criterion of success and the main determinant of how much bone and soft tissue are to be removed. Skeletal reconstruction: The average skeletal defect following adequate bone tumor resection measures 15 to 20 cm. Techniques of reconstruction vary and are independent of the resection, although the degree of resection may favor one technique over another. Soft tissue and muscle transfer: Muscle transfers are performed to cover and close the resection site and to restore motor power. Adequate skin and muscle coverage is mandatory. Distal tissue transfers are not used because of the possibility of contamination. Guidelines for limb sparing resection: No major neurovascular tumor involvement. Wide resection of the affected bone with a normal muscle cuff in all directions. En bloc removal of all previous biopsy sites and all potentially contaminated tissue. Resection of bone 3 to 4 cm beyond abnormal uptake, as determined by CT or MRI and bone scan. Resection of the adjacent joint and capsule. Adequate motor reconstruction, accomplished by regional muscle transfer. Adequate soft tissue coverage. Contraindications: Neurovascular involvement: Though vascular grafts may be utilized, the adjacent nerves are usually at risk, making successful resection less likely. In addition, the magnitude of resection in combination with vascular reconstruction is often prohibitive. Pathologic fractures: A fracture through a bone affected by tumor spreads tumor cells via the haematoma beyond accurately determined limits. The risk of local recurrence increases under such circumstances. If a pathologic fracture heals following neoadjuvant chemotherapy, a limb salvage procedure may be performed successfully. Inappropriate biopsy sites: An inappropriate or poorly planned biopsy jeopardizes local tumor control by contaminating normal tissue planes and compartments. Infection: The risk of infection after implantation of a metallic device or allograft in an infected area is prohibitive. Sepsis jeopardizes the effectiveness of adjuvant chemotherapy. Skeletal immaturity: The predicted leg length discrepancy should not be greater than 6 to 8 cm. Although, recently, expandable prostheses have been used with success in this situation. Upper extremity reconstruction is independent of skeletal maturity. Extensive muscle involvement: Enough muscle must remain to reconstruct a functional extremity. Amputation Definitive surgical treatment when limb-sparing resection is not a prudent option. A significant number of patients still require an amputation, despite the advent of limb-sparing surgery. Amputations for cancers tend to be at a higher (more proximal) anatomic level and to be technically more difficult, and the patients tend to be younger (reflecting the incidence of bone sarcomas). Psychological and cosmetic losses are also more substantial. Functional evaluation Six primary factors: motion, pain, stability and deformity, strength, emotional acceptance and function, and complications. Modular vs customized devices: no significant functional differences between arthrodesis, osteoarticular allografts, prosthetic arthroplasty, and rotationplasty. All are better than a prosthetic limb after above-knee (AK) amputation. Resections about the knee: no overall functional differences between arthrodesis, osteoarticular allografts, prosthetic arthroplasty, and rotationplasty. All are better than a prosthetic limb after above-knee (AK) amputation. Quality of life Rates of psychopathology do not differ significantly from those of the general population. Fertility is not a problem. Belief that the effort to save their limb was worthwhile. Less satisfaction in patients who had secondary amputations. Pain is usually minimal, when present most often associated with lower extremity amputation (pattern suggests a deafferentation syndrome). Among patients who did not do well, multiple symptoms, family problems and socioeconomic problems were more common than among patients who fared well. An amputee is less likely to marry than a limb-spared patient. Coping mechanisms of those with primary amputations are less effective than those of the limb salvage group. Patients who have limb salvage without later complications are very pleased with their outcome. Good work experience is an important compensation for physical loss. Male dependency needs are often underestimated. Men are left to manage their own adaptation tasks, whereas for females the opposite is true (female patients tend to become excessively dependent). Patients report no difficulty enjoying sexual activity. The first postsurgical sexual experience is described as no more traumatic than the first experience that required showing the leg (e.g., swimming). 3. Recognize the types of amputation and the underlying principles of prosthetic design. Principles of replacement arthroplasty The combination of stainless steel, titanium or cobalt-chrome for one component and high-density polyethylene for the other seems to give the best combination of low friction and good wear properties. Ceramic prostheses are also on trial. The articular surface should allow for adequate movement in the required directions whilst restraining movement in unwanted directions, to the extent that this is not prevented by ligaments damaged by disease. The prosthesis should be bonded to bone either by using acrylic cement or, more recently, coated or “sintered” components into which bone can grow. Hydroxyapatite in ceramic form has also been used as a coating and is claimed to bond chemically with bone. The operative procedure should be designed to reduce the risk of infection to a minimum. If failure occurs, it should be possible to remove the prosthesis, and, if necessary, perform an arthrodesis. Amputation considerations The more peripheral the amputation, the better, except that for any given level, a stump which is too long may make the fitting of an adequate prosthesis just below it very difficult or impossible. If the elbow or knee joints can be retained, function is very much improved. For most lower limb amputations, very adequate functional prostheses can be provided – the higher the amputation, the more difficult this becomes. Prosthetic function for upper limb amputations is relatively poor because of the complicated demands of hand function and the difficulty of replacing sensibility. The psychological preparation for amputation is very important and, indeed, amputation should usually be regarded as only a stage in a long-term program of rehabilitation. Amputation of toes Necessary for trauma and deformity. Rarely followed by functional loss (although big toe needed in walking). With penetrating ulcers, particularly in diabetes, may be necessary to amputate toe with associated metatarsal ray – gap closes and foot is functional. Amputation through the forefoot Usually for trauma, occasionally in diabetic ischaemia (not suitable for ischaemia due to large vessel disease). Good function, shoe needs padding. Amputation through the mid-tarsal region Usually better avoided. Amputation through the ankle A.k.a Symes amputation. The os calcis is shelled out of the heel, the skin is used as a flap to cover tibia and fibula, the malleoli are sawn off level. Gives a satisfactory end-bearing stump. For deformity and trauma. Prosthesis consists of a hinged foot on a shell designed to fit around the prominence of the ankle. The below-knee amputation Many indications. Optimal tibial section considered 17cm below the knee (<7cm unsatisfactory for prosthesis); fibula divided 2cm higher or at the same level as the tibia; a periosteal tube forms a firm bridge between the two ends. Equal anterior and posterior flaps are used. The most satisfactory prosthesis is the patellar-tendon-bearing limb (the end of the stump does not normally bear weight). Overall cosmesis can be very satisfactory. Mid-thigh amputation For ischaemia and trauma. Functionally less satisfactory than with the below-knee amputation. Stump should be as long as possible, but allow 12cm between the end and the position of the knee hinge of the prosthesis. Weight-bearing is taken through the ischial tuberosity. Well-fitted prosthesis can give a very satisfactory gait. Through-the-hip and hindquarter amputations For neoplasia. Mutilating and difficult to fit with a functional prosthesis.