Terry R. Malone

The Effects of Passive Warming on Muscle Injury

This study investigated the effects of passive warming on the biomechanical properties of the musculotendi nous unit. Paired tibialis anterior (TA) and extensor digitorum longus (EDL) muscles in the rabbit hindlimb were passively heated to different temperatures and then subjected to controlled strain injury. The parame ters examined were: 1) percent increase in length to failure, 2) force to failure, 3) energy absorbed by the musculotendinous unit to failure, and 4) site of failure. Warmed (39°C ± 0.5°C) TA (P ≤ 0.01) and EDL (P ≤ 0.05) muscles achieved a greater increase in length from rest before failing than did their contralateral con trols at 35°C ± 0.5°C. In both the TA and EDL the force at failure was greater at 35°C than at 39°C, although the difference was significant for only the EDL (P ≤ 0.05). The energy absorbed (area beneath the length-tension curve) by both the TA and EDL was greater at 39°C, but these differences were not signif icant. All muscles failed at the distal musculotendinous junction. These data suggest that passive warming increases the extensibility of the musculotendinous unit and may thereby reduce its susceptibility to strain in jury.

Cryotherapy-induced nerve injury

Cryotherapy is a frequently used therapeutic modality in the treatment of athletic injuries. Peripheral nerve injury can result from the use of cryotherapy and cause temporary disability for the athlete. Six cases of periph eral nerve injury are reviewed. All cases resolved spon taneously. To avoid this complication, one should con sider the location of major peripheral nerves, the thick ness of the overlying subcutaneous fat, and the duration of tissue cooling.

Long-term functional results in patients with anterolateral rotatory instability treated by iliotibial band transfer

The purpose of this paper is to define the use of the extraarticular, lateral reconstruction in the spectrum of patients with cruciate deficiency. A review was con ducted of 112 consecutive patients with a Maclntosh type iliotibial band transfer done between 1972 and 1986. Fifty-six of the patients had a partial or complete meniscectomy, and 24% had failed a previous extraar ticular procedure. Eighty-one percent were men, with a mean age of 23. Twenty-five percent of the patients had radiographic degenerative changes at the knee at the outset. Ninety-eight percent had an anterior drawer of 1 + or greater; 97% had a pivot shift greater than trace. All patients had symptomatic knee instability. Seventy-seven of the 112 patients (69%) were available for followup (range, 24 months to 15.5 years; median, 7.6). Twenty-three patients (21 %) returned for exami nation, KT-1000 and Cybex testing, and radiographs. An additional 54 patients (48%) were seen by their local physicians or returned a detailed questionnaire that included the Cincinnati knee rating scale. At final followup, 38% complained of some knee instability, 36% had recurrent effusions, 61 % had inter mittent pain, 79% had radiographic gonarthrosis, and 25% had undergone additional surgery. Forty-two per cent had a positive Lachman after surgery, and only 15% had a pivot shift. The mean knee score was 81.1. Previous extraarticular anterior cruciate ligament recon struction, meniscectomy, and generalized ligamentous laxity were associated with a significant decrement in the knee rating (P = 0.05). Ligamentous laxity strongly correlated with symptoms of giving way. Also, the incidence of pain, swelling, giving way, and activity modification correlated with meniscectomy and in creased as the length of followup increased for all patients. In conclusion, this study suggests that extraarticular lateral reconstruction does not restore normal knee function, but does eliminate the pivot shift and may decrease the incidence of repeat knee injury in selected patients with symptomatic cruciate deficiency. Lateral reconstruction alone should be limited to low-demand patients without previous meniscectomy, or general ized ligamentous laxity in whom more anatomic recon struction is not possible.