Posterior cruciate-retaining total knee arthroplasty for valgus osteoarthritis.

UNLABELLED: The valgus, osteoarthritic knee is challenging technically and it is unknown whether and how technical and implant variables influence outcomes. We therefore determined the influence of surgical technique of soft tissue balancing and patient and implant factors from 100 unselected cruciate-retaining TKAs for valgus osteoarthritis in patients younger than 75 years of age. From 1987 to 1990, lateral soft tissue balancing was done with an outside-in progression in which the lateral collateral ligament and popliteus were typically released from the femur. From 1991 to 1994, an inside-out technique was use in which the lateral collateral ligament and/or popliteus were typically preserved. The minimum followup was 0.1 year (mean, 8.2 years; range, 0.1-18.2 years). Fourteen of 16 revisions were for wear and/or instability. Popliteus release, lateral collateral ligament release, or greater polyethylene shelf age increased the risk of revision. At 10 postoperative years, survival (end point, revision) was 89% (100 knees), 94% when the shelf age was less than 1 year (n = 73 knees), 97% when the popliteus or lateral collateral ligament was not released (n = 57 knees), and 100% when both conditions were met (n = 39 knees). Cruciate-retaining implants can be successfully used in knees with any degree of valgus osteoarthritis and survival is improved when the surgeon preserves at least one of the structures providing lateral stability in flexion and uses polyethylene with a short shelf life. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Lack of bone accretion and amenorrhea: evidence for a relative osteopenia in weight-bearing bones.

Bone mineral density (BMD) was studied in young exercising amenorrheic girls to determine if density was compromised and the change related to injury. Ninety-eight volunteers (professional ballet dancers and controls) were studied in a cross-sectional study. Dancers and controls were further subdivided into normally cycling and amenorrheic subjects. Amenorrhea significantly lowered bone density of the spine (P less than 0.0001), wrist (P less than 0.03), and metatarsal (P less than 0.01); effects on the wrist were eliminated by controlling for age while controlling for weight eliminated all effects of amenorrhea at three sites. BMD of the metatarsal, a weight-bearing bone, showed an interaction between amenorrhea and dancing (exercising) P less than 0.035); surprisingly, dancing was associated with a further lowering of bone density. This interaction was eliminated when controlling for age, but not when controlling for weight. With multiple comparisons of the groups, spine, wrist, and metatarsal bone density was significantly lower in amenorrheic dancers when compared to normal dancers (P less than 0.05), even when controlling for age and weight in the metatarsal (P less than 0.05), and age in the spine (P less than 0.05). Estradiol levels correlated with bone density of both the wrist and the spine (r = 0.25, r = 0.23, P less than 0.02). Metatarsal density correlated with estradiol levels only in the dancers (r = 0.34, P less than 0.02). The only variable found to correlate with the occurrence of stress fractures was age of menarche. This was also the only variable of 9 (BMD of the wrist, spine or foot, calories ingested and expended, amount of calcium ingested, involvement in high energy activity, age of menarche or presence of amenorrhea) to predict stress fractures. Thus, BMD is significantly affected by the presence of amenorrhea but the effects are generally weight dependent. The compensatory increase in bone density generally seen in stressed bones, such as the metatarsal in ballet dancers, is deficient in amenorrheic premenopausal women even when controlling for weight but this effect may be age and estrogen dependent. Bone mass may not accumulate in the same manner in adolescents as in the mature women, thus putting them at risk for injury.

The role of selectivity in the pathogenesis of eating problems in ballet dancers.

Forty-nine dancers from four national ballet companies in America (N = 32) and the People's Republic of China (N = 17) were surveyed (mean age, 24.6 +/- 4.18) from highly and moderately selective dance companies. The less selected American dancers reported significantly more eating problems (46% vs 11%; P less than 0.05), anorectic behaviors (2.77 vs 1.11; P less than 0.05), and familial obesity (42% vs 5%; P less than 0.05) than the Americans chosen from a company school. Differences were not found on these variables between the highly selected American and Chinese dancers. All of the groups reported a delay in menarche and weighed approximately 14% below their ideal weight for height. These data suggest that dancers who have survived a stringent process of early selection may be more naturally suited to the thin body image demanded by ballet and so less at risk for the development of eating problems. In addition, delayed menarche is typical of the majority of national dancers and probably is reflective of genetic and environmental factors.

Pain in the posterior aspect of the ankle in dancers. Differential diagnosis and operative treatment.

A retrospective review was performed of the results of operative treatment of stenosing tenosynovitis of the flexor hallucis longus tendon or posterior impingement syndrome, or both, in thirty-seven dancers (forty-one operations). The average duration of follow-up was seven years (range, two to thirteen years). The results were assessed with use of a questionnaire for all patients, and a clinical evaluation was performed for twenty-one patients (twenty-two ankles). Twenty-six operations were performed for tendinitis and posterior impingement; nine, for isolated tendinitis; and six, for isolated posterior impingement syndrome. A medial incision was used in thirty-three procedures; a lateral incision, in six; an anterior and a medial incision, in one; and a lateral and a medial incision, in one. Thirty ankles had a good or excellent result; six, a fair result; and four, a poor result. (The result of the second procedure on an ankle that was operated on twice was not included.) The result was good or excellent for twenty-eight of the thirty-four ankles in professional dancers, compared with only two of the six ankles in amateur dancers.

Cuboid subluxation in ballet dancers.

Cuboid subluxation is a common but poorly recognized condition. Its symptoms include lateral midfoot pain and an inability to "work through the foot." In addition, pressing on the plantar surface of the cuboid in a dorsal direction produces pain. The normal dorsal/plantar joint play is reduced or absent when compared to the uninjured side, and subtle forefoot valgus is present. Frequently, there is a shallow depression on the dorsal surface of the foot and palpable fullness on the plantar aspect of the cuboid. Documentation by radiograph, CT scan, or magnetic resonance imaging is difficult because of the normal variations found in the relationship between the cuboid and its surrounding structures. The diagnosis is primarily subjective, and must be made on the basis of the patient's history and physical findings. Treatment requires recognition of the condition, manual reduction by a therapist or physician familiar with the condition, and follow-up to be certain that the cuboid remains in place. Therapists and orthopaedists involved in the care of dancers should be alert to the possibility of cuboid subluxation and be able to recognize it when it occurs.

A profile of the musculoskeletal characteristics of elite professional ballet dancers.

Twenty-eight principal dancers and soloists from America's two most famous ballet companies were examined for anthropometric measurements, including flexibility, muscle strength, and joint range of motion. Both male and female dancers were flexible, but not hypermobile, and did not differ significantly from each other. Marked differences were found between the range of motion of the hip and ankle in the dancers and the norms for the general population. The increased external rotation of the hip in women was accompanied by a loss in internal rotation, resulting in an increased range of motion with an externally rotated orientation. The men, however, lost more internal rotation than they gained in external rotation. These data raise the possibility of a torsional component to the turned-out hip position in elite female professional ballet dancers. In addition, significant anatomic differences separate elite dancers of both sexes from the normal population.

Fractures of the distal shaft of the fifth metatarsal. "Dancer's fracture".

We retrospectively reviewed the office records of the senior author--which include two national ballet companies--and identified 35 dancers who sustained distal shaft fractures of the fifth metatarsal. The usual fracture pattern is a spiral, oblique fracture starting distal-lateral and running proximal-medial. Treatment consisted of open reduction and internal fixation for 2 patients, closed reduction and percutaneus fixation for 2 patients, short leg weightbearing cast for 7 patients, and an elastic wrap and treatment of symptoms for 24 patients. Patients with marked displacement of the fracture underwent internal fixation early in the study period; but more recent treatment emphasized nonoperative means, even for displaced fractures. The average time to pain free walking was 6.1 weeks (range, 0 to 16); return to barre exercises, 11.6 weeks (range, 4 to 48); and return to performance, 19 weeks (range, 6 to 52). There was one delayed union (7 months) and one refracture (2 months) that subsequently healed. All patients returned to professional performance without limitation and no patient reported pain with performance at followup. Spiral fractures of the distal shaft of the fifth metatarsal are common injuries and can usually be treated nonoperatively for these high performance athletes without long-term functional sequelae.

Personality, stress, and injuries in professional ballet dancers.

Twenty-nine soloist and principal dancers (mean age, 29.08 years) from America's two most celebrated ballet companies were administered questionnaires measuring personality (API), occupational stress (OES), strain (PSQ), and coping mechanisms (PRQ), and injury patterns. The results revealed that male dancers demonstrated significantly more negative personality traits and psychological distress than female dancers or men in the general population. In addition, physical stress and personality traits, characteristic of the "overachiever," distinguished injured dancers. It is suggested that classical ballet's emphasis on the ballerina may be at odds with a masculine identity in male dancers. Furthermore, the qualities that lead to success in this profession may contribute to injuries if carried to an extreme.

Foot and ankle injuries in dancers.

Dancing is not dangerous; however, dancers must recognize their limitations and learn to do the best they can with what they have to work with. This article discusses some of the more common acute and chronic foot and ankle problems in dancers for the benefit of the treating physician.

Roger Mann Award 1995. Capsular interposition arthroplasty for severe hallux rigidus.

Thirty patients (37 feet) with severe hallux rigidus underwent resection arthroplasty of the first metatarsophalangeal joint with our modification (reattachment of the extensor hood and extensor brevis to the flexor hallucis brevis as a capsular interposition arthroplasty, with minimal bone resection). Pain and function were significantly improved. Transfer metatarsalgia was not seen. All patients had at least 4/5 plantarflexion strength and averaged 50 degrees of dorsiflexion. In patients with severe hallux rigidus and nearly equal length of first and second metatarsals, capsular interposition arthroplasty offers a surgical option that relieves pain without sacrificing motion or strength.

Stress fractures at the base of the second metatarsal in ballet dancers.

Stress fractures are a frequent injury in ballet companies and the most common location is at the base of the second metatarsal. While previous reports have focused on risk factors for this injury (overtraining, delayed menarche, poor nutrition), there is no published series describing the natural history and outcome following this fracture. We reviewed the office records of the senior author and identified 51 professional dancers (64 fractures) who sustained a stress fracture at the base of the second metatarsal. History of a previous stress fracture in the lower extremity was seen in 19 patients and delayed menarche in the women was common. The clinical presentation was insidious onset of midfoot pain an average of 2.5 weeks prior to seeking medical care. The initial radiographs of the foot were positive in 19 patients, questionable in 3 patients, and negative in 42 patients. The usual location of the fracture was at the proximal metaphyseal-diaphyseal junction (three fractures extended into the tarsometatarsal joint). Treatment consisted of a short leg walking cast for 6 patients, and a wooden shoe and symptomatic treatment for the remainder. At follow-up, 14% of patients still had occasional pain or stiffness in the midfoot with dancing. The patients returned to performance at an average of 6.2 weeks following diagnosis. No patients required bone grafting for persistent symptoms. There were eight refractures (at the same site) occurring an average of 4.3 years, all of which healed with conservative care. Stress fractures at the base of the second metatarsal are common in ballet dancers and can usually be treated with symptomatically. The results of this study are discussed in terms of risk factors, the use of a posterior-anterior view of the foot to eliminate overlap at Lisfranc's joint, and our present treatment regimen.

Hallux rigidus. Excisional arthroplasty.

The authors feel that capsular interposition arthroplasty can give predictable pain relief in carefully selected individuals with severe (grade III) hallux rigidus. Attention to the relative lengths of the first and second metatarsals, minimal shortening of the proximal phalanx, and use of the dorsal capsule and EHB tendon as an interposition all contribute to good to excellent objective and subjective results. Approximately 30% of patients undergoing this procedure experience some degree of transfer metatarsalgia postoperatively and probably require orthoses for sports. The authors feel that this operation presents a reasonable alternative to many patients who are candidates for an arthrodesis of the first MTP joint for advanced degenerative disease.

Problems of the second metatarsophalangeal joint.

Diagnosis and treatment of second metatarsophalangeal joint problems are discussed. A new staging for Freiberg's disease is presented with differential treatment for each stage. Subluxation of the second metatarsophalangeal joint occurs commonly but is often unrecognized. A simple test in physical examination, the "positive Lachman" of the metatarsophalangeal joint is illustrated and explained. Although controversial, the etiology of synovitis of the second metatarsophalangeal joint is probably diverse; it can occur idiopathically or because of mechanical instabilities relating to malalignment of the first ray or disproportionate length of the second ray. When conservative treatment fails, surgical debridement of the joint is indicated. The second metatarsophalangeal is the most common chronically dislocated joint in the foot. The surgical goal is a reduced metatarsophalangeal joint and a stable toe. Surgical correction detailed by the authors involves a stepwise approach depending on the severity of the contracture, bony overlap, and deformity.

Differential diagnosis and treatment of posterior ankle pain in dancers and equinus athletes.

Posterior ankle pain in dancers and equinus athletes is often caused by the extreme plantarflexion requirements of their activity. Differentiation between true posterior ankle pain and Achilles tendon pain is discussed. Signs and symptoms of posterior ankle pain are specific to the flexor hallicus tendon on the medial side or impingement when on the lateral side. Surgical exploration as well as conservative treatment is discussed.

Sprained ankles in ballet dancers.

Ankle sprains are common in dancers. They result from working in the positions which allow increased risk of sprain on the lateral side of the ankle for many hours a day. One hundred ankle injuries were evaluated. The mechanisms of injury are presented, as well as a classification of these injuries. The recommended treatment and rehabilitation are discussed. Leg muscle strength must be restored before rehabilitation is considered complete.