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turę, a gap in the patclla may bc palpable if not too much hematoma has accumulatcd to obscure it.

Extensor Mechanism. Palpation of other portions of thc extensor mechanism is indicated if the history or inspec-tion raises the question of localized pathology. Figurę 6-31 shows the common sites of tenderness in Osgood-Schlatter disease, Sinding-Larsen-Johansson disease, patellar tendinitis, and ąuadriceps tendinitis. In the presence of quadriceps tendon rupture, the examiner may bc able to palpate a gap as well as tenderness when the paticnt attempts to perform a straight-leg raise. Palpating the patellar tendon during an attempted straight-leg raise is also a good way to check for rupture of this structure. Normally, the patellar tendon can be easily felt to tense during this maneuver. If the tendon is ruptured, it remains flaccid, and a gap, usually just distal to the patella, may be palpable (see Fig. 6-23).

Jumpers knee is the generał term that includes prox-imal patellar tendinitis, distal patellar tendinitis, and quadriceps tendinitis. By far the most common location is in thc proximal patellar tendon just distal to thc infe-rior tip of the patella. In addition to eliciting pain, the examiner should feel a spongy crepitant sensation when firmly palpating this area with a fingertip. Palpable or vis-ible swelling of the tendon is present in morę severe cases of patellar tendinitis.

MEDI AL ASPECT

Medial Joint Linę. Palpation for tibiofemoral joint linę tenderness is another important part of a basie knee examination. The joint lines are most easily identified by asking the patient to flex the knee to 90°. This may be done in either the seated or the supine position (see Fig. 6-9). As mentioned elsewhere, flexion causes the femur to roli posteriorly on the tibia and makes the anterior joint linę morę visible. The examiner identifies the anterior portion of the medial joint linę with an index finger and then repeatedly presses with the tip of the finger while pro-gressing posteriorly around the side of the joint (Fig. 6-32). The finding of tenderness at thc middlc to thc pos-terior portions of either joint linę is highly suspicious for pathology localized to thc tibiofemoral compartment, most commonly a meniscus tear or osteoarthritis.

Tenderness that is elicitcd only at the anterior portion of the joint linę is usually nonspccific. An exception to this statement is found in the knee that is locked, or unable to fully extcnd, owing to a displaced bucket handle fragment of a tom medial meniscus. In this condition, a longitudinal tear allows a long strip of meniscus to dis-place anterior to the medial femoral condyle and prevent extension. In the presence of such an injury, exquisitc tenderness usually is found at the point where the curvature of the medial femoral condyle meets the medial joint linę (Fig. 6-33). Bucket handle tears also occur in the lateral meniscus, although much less often, but such a charac-teristic point of tenderness is found less frequently than in medial meniscus tears.

Knee 221

Chapti-r 6

Figurę 6-32. Palpation of thc medial joint linę.

Medial Collateral Ligament. The collateral ligaments are superficial and should be palpated when injury to them is suspcctcd. To palpate the MCL, identify the medial epicondyle and palpate progressively distally and obliquely across the medial joint linę to the tibia portion of thc ligament (Fig. 6-34A). Careful palpation usually

Figurę 6-33. Palpation of the typical point of maximal tenderness in a patient with a locked knee due to a displaced bucket handle tear of the medial meniscus.