Comparison of males' and females' ratios of anterior-cruciate-ligament width to femoral-intercondylar-notch width: a cadaveric study.

The relative incidence of anterior cruciate ligament (ACL) injuries has been reported to be significantly higher in females than in males. Although many hypotheses have been proposed for this discrepancy, no conclusive explanation has reached consensus opinion. The purpose of this study was to evaluate and compare fresh-frozen cadaveric knee specimens to determine whether there is a significant difference between males' and females' ratios of ACL width to femoral intercondylar notch (FIN) width. We evaluated 15 male knees and 11 female knees. Data regarding sex, age, side (right or left), and ACL and FIN widths were obtained for all specimens. Age of male specimens ranged from 48 to 84 years (mean, 63.9 y); age of female specimens ranged from 33 to 96 years (mean, 69.9 y). Mean ACL width, mean FIN width, and their ratios were calculated. In the male specimens, mean ACL width was 10.59 mm (SD, 1.30 mm), mean FIN width was 20.18 mm (SD, 2.20 mm), and mean ACL:FIN width ratio was .526 +/- 0.047 (52.6% +/- 4.7% of FIN width); in the female specimens, mean ACL width was 8.09 mm (SD, 1.12 mm), mean FIN width was 20.50 mm (SD, 1.69 mm), and mean ACL: FIN width ratio was .393 +/- 0.03 (39.3% +/- 3% of FIN width). Results showed statistically significant differences between males' and females' ACL widths (P < .001) and between their ACL: FIN width ratios (P< .001) but not between their FIN widths. The significant difference between males' and females' ACL widths may be related to the general size differences between the groups. It has been speculated that female athletes' smaller ACLs may predispose them to ACL ruptures. Perhaps more significant is the difference between males' and females' ACL: FIN width ratios, which are significantly smaller in females compared with males. This may be directly related to the cause of more ACL ruptures in females. Further studies, including a good mechanical model, will help elucidate whether this anatomic discrepancy correlates clinically.

Musculocutaneous nerve entrapment revisited.

Compression of the lateral cutaneous nerve of the forearm (LCNF), the distal sensory termination of the musculocutaneous nerve, can occur below the biceps aponeurosis, most commonly after strenuous elbow extension or forearm pronation. Between 1965 and 1992, 15 patients reported pain in the anterolateral elbow with "burning" into the forearm. There was a minimum 2-year follow-up of all patients in the study (average 13.4 years, median 15 years). All patients were managed conservatively for 12 weeks. Of the 15 patients, 11 required operative decompression that involved resecting a triangular wedge of aponeurosis overlying the nerve. Of the four nonoperative patients, one had persistent hypesthesia even though pain was relieved and range of motion was restored. Of the 11 patients treated operatively, none had recurrence of hypesthesia, and all patients continued to have complete relief of pain and full range of motion. One additional patient required surgery for lateral epicondylitis 2 years later. There were no operative complications.

Cryopreserved anterior cruciate ligament allografts in a canine model.

This study was done to determine the clinical and biomechanical properties of cryopreserved anterior cruciate ligament allografts at 3, 6, 9, and 24 months after transplantation. A companion study of autografts was done to evaluate the effects of the surgical procedure and preservation on the tissue. The knee joints of 69 mongrel dogs (allograft n = 34, autograft n = 35) weighing 17 kg to 25 kg were grafted. Biomechanical results showed that maximum load was less in allografts than in autografts at each time interval. Deformation and slope were not significantly different between allograft and autograft. An apparent delay in revascularization and cellular repopulation was found in allografts compared with autografts, and collagen type I/type III ratios were similar in both grafts. DNA analysis indicated complete replacement of DNA in the graft by the host. Allografts provide adequate functional stability for daily activities in the canine model up to 2 years after transplantation. Biomechanical properties were relatively poor in allografts, which may lead to failure under more strenuous activity. The biologic similarity to autografts may indicate future remodeling potential.

Brachial artery compression by the lacertus fibrosus.

Five patients presented with classic symptoms diagnostic of intermittent claudication that were exacerbated by strenuous activity. Examination demonstrated localized tenderness over the lacertus fibrosus (bicipital aponeurosis), as well as increased pain and an obliterated radial pulse with forearm pronation and resisted elbow flexion. All 5 were athletes who had hypertrophied forearm muscles. Patients were diagnosed with brachial artery compression by the lacertus fibrosus. Release of the lacertus fibrosus restored normal pulses in all cases. Followup ranged from 6 months to 25 years. Full clinical recovery was achieved in 3 patients. One patient had a good result and 1 a fair result. Although the lacertus fibrosus has been well described as a cause of neural compression and compartment syndrome, it has been reported only once to cause intermittent arterial compromise. Hypertrophy of the muscles and the lacertus fibrosus related to excessive use is an important factor in the development of isolated vascular, neural, or combined neurovascular lesions.

Longitudinal rupture of the peroneal tendons.

To determine more precisely the injury mechanism of the peroneal tendon longitudinal tear, we studied 15 cadaveric lower extremities. Our study was motivated by our observation from a retrospective study of athletes treated by one surgeon (FHB) over a 17-year period. Eight patients who sustained lateral ankle sprains by plantar flexion and inversion of the foot on the leg also had longitudinal tears (1 to 3 cm) of the peroneal tendon--five in the peroneus longus and three in the peroneus brevis. All of the lateral ankle sprains were successfully managed nonoperatively. However, even after a period of rehabilitation, when their ankles should have been asymptomatic, the patients continued to complain of persistent lateral ankle swelling, popping, and retrofibular pain. On physical examination, all ankles were clinically stable. Palpable retrofibular popping occurred with active foot rotation. There was no evidence of peroneal tendon instability. Radiographs were normal and tenograms were suggestive of peroneal tendon injury but did not have the specificity to reveal the rupture. Primary suture repair of this peroneal tendon split was performed and gave excellent long-term results. The cadaveric studies revealed that the tear of the tendon could occur in the 25 degrees to 15 degrees range of plantar flexion as the peroneus longus impinged against the tip of the fibula and as the peroneus brevis impinged against the lateral wall of the peroneal groove or against the longus tendon.

When Cryotherapy Injures.

In brief Cryotherapy is a readily accessible, inexpensive modality for treating acute athletic injuries. However, prolonged cryotherapy can cause peripheral nerve injury, especially in athletes who have little subcutaneous fat. The six cases reported here resolved spontaneously within 6 months. Simple measures that can help avoid nerve injury include compensating for the thickness of the patient's subcutaneous fat, limiting the duration of treatment, and applying an insulating material between the cold source and the patient's skin.

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 peripheral nerve injury are reviewed. All cases resolved spontaneously. To avoid this complication, one should consider the location of major peripheral nerves, the thickness of the overlying subcutaneous fat, and the duration of tissue cooling.

Osseous injury associated with acute tears of the anterior cruciate ligament.

Multiplanar spin-echo magnetic resonance imaging was performed on 54 patients with acute complete anterior cruciate ligament tears. Imaging was done within 45 days of index anterior cruciate ligament injury. Spin-echo T1- and T2-weighted images were used to determine the lesion morphology and location. Only the T2-weighted sagittal images were used for the incidence assessment; T2-weighted spin-echo imaging reflects free water shifts and best indicates the acute edema and inflammatory changes from injury. Eighty-three percent (45 of 54) of the knees had an osseous contusion directly over the lateral femoral condyle terminal sulcus. The lesion was highly variable in size and imaging intensity; however, the most intense signal was always contiguous with the subchondral plate. Posterolateral joint injury was seen in 96% (43 of 45) of the knees that had a terminal sulcus osseous lesion determined by magnetic resonance imaging. This posterolateral lesion involves a spectrum of injury, including both soft tissue (popliteus-arcuate capsuloligamentous complex) and hard tissue (posterolateral tibial plateau) injuries. The consistent location of the osseous and soft tissue injuries underscores a necessary similar mechanism of injury associated with these acute anterior cruciate ligament tears. Based on these characteristic findings, several proposed mechanisms of injury are discussed.

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 conducted of 112 consecutive patients with a MacIntosh-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 extraarticular 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 examination, 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 intermittent pain, 79% had radiographic gonarthrosis, and 25% had undergone additional surgery. Forty-two percent 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 reconstruction, 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.(ABSTRACT TRUNCATED AT 250 WORDS)

An algorithm for arthroscopy in the over-50 age group.

We conducted a retrospective study to identify the preoperative variables that correlated with a successful outcome for knee arthroscopy in patients over the age of 50. We mailed questionnaires to 94 patients (57 responded) and reviewed their medical records and radiographs. A modified Hospital for Special Surgery knee rating system was devised. The average follow-up was 33 months. The percentage of those who felt they had successful results decreased with time: 82.8% felt their knees had improved immediately after postoperative rehabilitation; this decreased to 78.1% at 6 months, 73.5% at 1 year, 65.5% at 2 years, and 50.0% at 3 years. Therefore, the subjective success rate was 67%. We performed statistical analysis of all variables to determine which had a beneficial or detrimental effect on outcome. In addition, we devised an equation to allow postoperative prediction of score. We found that age was not a factor and that radiographic findings had the greatest impact on postoperative results.

Syndesmosis sprains of the ankle. The influence of heterotopic ossification.

A retrospective study of 50 syndesmosis sprains in 44 football players was performed. Five patients (6 ankles) were lost to follow-up, allowing review of 44 injuries. Average follow-up was 47 months. The patients were evaluated for recurrent injury, overall ankle function, and for persistent ankle symptoms, including stiffness, pain, limping, and swelling. Follow-up radiographs of the injured ankle were obtained in 22 patients. The average return time to full activity was 31 days. Pain with pushing-off was a major factor preventing return to activity. At final followup, 36% of the patients complained of persistent mild to moderate stiffness of the ankle. Twenty-three percent had mild to moderate pain, usually with activity. One patient had a mild limp with activity, and 18% of the ankles had persistent mild to moderate swelling. Ankle function was rated as good to excellent in 86%. All patients with fair results had recurrent ankle sprains. There were no poor results. Eleven of the 22 patients with follow-up radiographs developed heterotopic ossification within the interosseous membrane, but no patient developed a frank synostosis. The patients with heterotopic ossification required an average of 11 days more recovery time than those without ossification. There was no significant difference between the 2 groups' ultimate ratings of ankle function or ankle symptoms, but the ankles with heterotopic ossification were associated with more recurrent lateral ankle sprains. We conclude that syndesmosis sprains require a longer recovery period than other types of ankle sprains. Most of these injuries showed good to excellent ankle function after recovery, unless there was a recurrent ankle sprain.2+ formation of heterotopic ossification.

Nerve injury in athletes caused by cryotherapy.

Cryotherapy is a therapeutic modality frequently used in the treatment of athletic injuries. In very rare circumstances, inappropriate use in some individuals can lead to nerve injury resulting in temporary or permanent disability of the athlete. Six cases of cold-induced peripheral nerve injury from 1988 to 1991 at the Sports Medicine Center at Duke University are reported. Although disability can be severe and can render an athlete unable to compete for several months, each of these cases resolved spontaneously. Whereas the application of this modality is typically quite safe and beneficial, clinicians must be aware of the location of major peripheral nerves, the thickness of the overlying subcutaneous fat, the method of application (with inherent or additional compression), the duration of tissue cooling, and the possible cryotherapy sensibility of some individuals.

Abdominal musculature abnormalities as a cause of groin pain in athletes. Inguinal hernias and pubalgia.

There has been increasing interest within the European sports medicine community regarding the etiology and treatment of groin pain in the athlete. Groin pain is most commonly caused by musculotendinous strains of the adductors and other muscles crossing the hip joint, but may also be related to abdominal wall abnormalities. Cases may be termed "pubalgia" if physical examination does not reveal inguinal hernia and there is an absence of other etiology for groin pain. We present nine cases of patients who underwent herniorrhaphies for groin pain. Two patients had groin pain without evidence of a hernia preoperatively (pubalgia). In the remaining seven patients we determined the presence of a hernia by physical examination. At operation, eight patients were found to have inguinal hernias. One patient had no hernia but had partial avulsion of the internal oblique fibers from their insertion at the public tubercle. The average interval from operation to return to full activity was 11 weeks. All patients returned to full activity within 3 months of surgery. One patient had persistent symptoms of mild incisional tenderness, but otherwise there were no recurrences, complications, or persistence of symptoms. Abnormalities of the abdominal wall, including inguinal hernias and microscopic tears or avulsions of the internal oblique muscle, can be an overlooked source of groin pain in the athlete. Operative treatment of this condition with herniorrhaphy can return the athlete to his sport within 3 months.

Team physician #9. The role and responsibilities of the competition physician.

The rapid growth of participation in contact sports has been accompanied by an increasing need for sporting event coverage by qualified physicians. The competition physician must not only be capable in contemporary emergency and sports medicine, but must also have organizational skills to coordinate satisfactory medical and ancillary backup. This monograph outlines a comprehensive plan for efficient preparation and execution of on-site sports injury assessment and care. With knowledge, organization, and preparation, competition coverage can be a satisfying component of a sports medicine practice.

The prolonged burner syndrome.

Over the course of a single football season, six players evaluated by the medical staff had burners that displayed a prolonged neurologic recovery. These players were examined and subsequently evaluated with isokinetic testing and electrodiagnostic studies to elucidate better the short-term natural history of the prolonged burner syndrome. Evidence of muscular weakness at 72 hours postinjury best correlated with positive electrodiagnostic findings. No correlation was found between the initial physical examination findings and the results of electrodiagnostic testing. Isokinetic strength evaluation demonstrated many relative strength differences that were difficult to discern with manual muscle testing. The return of a player to athletic competition following this injury should largely be based on the clinical examination.