Injuries in women's professional soccer.

OBJECTIVE: The injury data from the first two seasons of the Women's United Soccer Association (WUSA) were analysed to determine the injury incidence, anatomic location of injuries, and relation of player position. METHODS: Injury data on 202 players from eight teams during the first two seasons of the WUSA were prospectively collected and analysed. RESULTS: A total of 173 injuries occurred in 110 players with an overall injury incidence rate of 1.93 injuries per 1000 player hours. The incidence of injury during practice and games was 1.17 and 12.63 per 1000 player hours, respectively. Of the injuries 82% were acute and 16% were chronic. Most of the injuries (60%) were located in the lower extremities. Strains (30.7%), sprains (19.1%), contusions (16.2%), and fractures (11.6%) were the most common diagnoses and the knee (31.8%) and head (10.9%) were the most common sites of injury. Anterior cruciate ligament (ACL) injuries accounted for 4.6% of all injuries and the incidence of ACL tears was 0.09 per 1000 player hours (practice 0.04, game 0.90). Midfielders suffered the most injuries (p<0.007). CONCLUSION: We conclude that the injury incidence in the WUSA is lower than the 6.2 injuries per 1000 player hours found in the corresponding male professional league (Major League Soccer); however, knee injuries predominate even in these elite female athletes.

Practical considerations in anterior cruciate ligament replacement surgery.

The endoscopic method of anterior cruciate ligament (ACL) reconstruction using a patellar tendon graft that is secured with interference screws is a commonly performed procedure. It has many potential pitfalls, the majority of which are secondary to technical errors. Prevention of errors starts with a full knowledge of normal ACL anatomy and any discrepancies with the size and shape of the graft substitute. Accurate tibial and femoral tunnel placement is essential and involves using consistent intra-articular landmarks and achieving specific radiographic criteria. Accurate tunnel placement minimizes graft excursion and impingement against the roof of the intercondylar notch. This will result in maximum knee stability and motion. Much has been written about the principles of graft-tunnel mismatch and interference screw-bone plug divergence. The clinical implications of these potential sources of error remain somewhat controversial and are discussed in this article.

Development of a virtual reality arthroscopic knee simulator.

The virtual reality arthroscopic knee simulator (VR-AKS) consists of a computer platform, a video display, and two force-feedback (haptic) interfaces which also monitor the position of the instruments in the user's hands. The forces that the user would normally apply to the lower limb during arthroscopy are directed through an instrumented surrogate leg. Proprietary software furnishes the mathematical representation of the physical world and replicates the visual, mechanical, and behavioral aspects of the knee while task-oriented programs monitor and record specific areas of user performance. A prototype has demonstrated the feasibility of the system and work on the first, fully functional simulator will begin soon.

Photodynamic modulation of wound healing with BPD-MA and CASP.

BACKGROUND AND OBJECTIVE: Wound healing is an intricate process requiring the orchestration of cells, growth factors, cytokines, and the extracellular matrix. Cytokines, specifically TGF-beta, are believed to be instrumental in sustaining the fibrotic process, which leads to scarring. Photodynamic therapy (PDT) uses potent photosensitizers, which induce a wide range of effects on cells and the extracellular matrix. The influences of PDT on wound healing are not well known. STUDY DESIGN/MATERIALS AND METHODS: Seven full-thickness incisional wounds were placed on each of 24 hairless Sprague Dawly rats, three wounds on one flank serving as dark controls and four on the contralateral side treated with PDT. Wounds were created two days before, one hour before, or one hour after red light exposure with an argon ion pumped dye laser. Twelve rats were injected with 0.25 mg/kg or 0.5 mg/kg of the PDT drug, BPD-MA, and the other 12 with 5 mg/kg or 10 mg/kg of the PDT drug, CASP, 3 and 24 hours prior to irradiation of light, respectively. At low doses of both photosensitizers, animals were irradiated with 1, 5, 10, and 20 J/cm2. At higher doses of BPD-MA and CASP animals were treated with 10, 20, 50, and 100 J/cm2 of light. Wounds were examined each day for 14 days and noted for edema, erythema, inflammation, necrosis, and quality of scarring. Wounds were also photographed at day 0, 2, 5, 8, and 14 post-irradiation. All animals were sacrificed 14 days after irradiation and the wounds were evaluated by light microscopy. RESULTS: Grossly, animals treated with 0.25 mg/kg BPD-MA showed no effect with PDT. Animals treated with 0.5 mg/kg BPD, and 5 and 10 mg/kg CASP showed responses that varied with both light and drug dose. Erythema, edema, inflammation, and necrosis attributed to PDT were all observed, but there was no apparent influence of PDT on either the rate or final appearance of wound healing. Histologically, there were no apparent differences between treated and untreated sites, regardless of the drug, dose of light, or time of irradiation. CONCLUSION: A single PDT treatment given before or after skin wounds does not apparently alter wound healing even when PDT caused brisk inflammatory reactions. PDT may have effects that were not detected. We conclude that PDT does not greatly influence incisional skin wound healing in the rat model.

Lipoma arborescens of the knee.

Lipoma arborescens is a rare intra-articular lesion, characterised by diffuse replacement of the subsynovial tissue by mature fat cells, producing prominent villous transformation of the synovium. The aetiology of this benign condition is unknown. We describe six cases involving the knee, discussing the symptoms, diagnosis and treatment.

The thermal properties of bovine joint capsule. The basic science of laser- and radiofrequency-induced capsular shrinkage.

Orthopaedic surgeons have recently adapted the holmium: yttrium-aluminum-garnet (YAG) laser for the shrinkage of capsular tissues for treatment of glenohumeral instability. The molecular mechanism of capsular shrinkage has not been documented to date. This study examined the effects of heating on bovine calf knee capsule and subsequent shrinkage of the capsule. Capsule specimens were placed in a saline bath at temperatures ranging from 55 degrees to 75 degrees C for 1, 3, 5, and 10 minutes. Shrinkage was quantified by digital imaging, and the tissue was examined by light and polarized light microscopy. Tissue contraction was not measurable at or below 57.5 degrees C. At 60 degrees C, tissue shrinkage occurred with corresponding basophilic staining and loss of birefringence in collagen fibers. For specimens heated at 60 degrees C and 62 degrees C, shrinkage directly correlated with duration of thermal exposure. Maximal shrinkage of approximately 50% in length occurred at and above 65 degrees C with thermal exposures of 1 minute or greater. This study demonstrates that thermal shrinkage of bovine knee capsule correlates with denaturation of collagen fibers and depends on both time and temperature. Capsular shrinkage treatments may be performed with any energy source that is capable of well-controlled heating of capsular tissue and does not depend on the special properties of laser light.

Direct injury to the axillary nerve in athletes playing contact sports.

We performed long-term followup (31 to 276 months) of 11 contact athletes who had sustained isolated injuries to their axillary nerves during athletic competition. There were no known shoulder dislocations. Electromyographs were taken of 10 patients, and all patients had confirmation of clinically defined injuries that were confined to their axillary nerves. Nine injuries were sustained while tackling opposing players in football; two were sustained in hockey collisions. In seven athletes, the mechanism of injury was a direct blow to the anterior lateral deltoid muscle. In four athletes, there were simultaneous contralateral neck flexion and ipsilateral shoulder depression. At followup, all patients had residual deficits of axillary sensory and motor nerve function. There had been no deltoid muscle improvement in three patients, moderate improvement in two patients, and major improvement in six patients. However, shoulder function remained excellent, with all athletes maintaining full range of motion and good-to-excellent motor strength. Axillary nerve exploration and neurolysis in four patients did not significantly affect the outcomes. Although no patient had full recovery of axillary nerve function, 10 of 11 athletes returned to their preinjury levels of sports activities, including professional athletics.

Diagnosis and treatment of traumatic anterior instability of the shoulder.

Traumatic anterior glenohumeral joint dislocation is the most common type of shoulder instability. Lesions that usually result are avulsion of the anterior capsule and glenoid labrum from the glenoid rim (Bankart lesion), compression fracture of the posterosuperior humeral head (Hill-Sachs lesion), and laxity of the joint capsule. Another common lesion is a lengthwise disruption of the rotator cuff at the interval between the subcapularis and supraspinatus tendons. The shoulder that dislocates repeatedly after trauma has an excellent success rate when treated by surgical repair. The aim of the Bankart procedure is to restore stability to the shoulder by repairing the traumatic lesion of the anterior glenoid rim without altering normal anatomy.

Anterior shoulder stabilization using the bankart procedure.

The primary pathological lesion in traumatic anterior glenohumeral dislocation and subluxation is avulsion of the anterior shoulder capsule and ligaments from the glenoid rim (Bankart lesion). The Bankart procedure is a method of repairing this lesion: a direct suturing of the avulsed capsule to the bone. A deltopectoral approach is used, and the conjoined tendon is retracted medially. A T-shaped incision is made in the subscapularis tendon and muscles, and a T-shaped capsular incision gives exposure to the anterior glenoid rim and Bankart lesion. The avulsed capsule is repaired to bone with sutures passed through the glenoid rim or with suture anchors.

Reconstruction of the lateral ankle ligaments. A biomechanical analysis.

UNLABELLED: The purpose of this study was to perform a biomechanical analysis of several commonly performed operative procedures used to stabilize the lateral ankle. We performed the Evans, Watson-Jones, and Chrisman-Snook procedures on 15 cadaveric ankles and tested the ankles for stability, motion, and isometry of graft placement. The Evans procedure allowed increased anterior displacement, internal rotation, and tilt of the talus when compared to ankles with intact ligaments. Subtalar joint motion was restricted by the Evans procedure. The Watson-Jones procedure controlled internal rotation and anterior displacement of the talus, but was less effective in controlling talar tilt and also restricted subtalar joint motion. The Chrisman-Snook procedure allowed increased internal rotation and anterior displacement of the talus when compared to ankles with intact ligaments. The procedure was effective in limiting talar tilt, but restricted subtalar joint motion. Based on the biomechanical data obtained, we devised a lateral ankle reconstruction with bone tunnels that reproduce the anatomic orientation of both the anterior talofibular and calcaneofibular ligaments. This ankle ligament reconstruction resists anterior displacement, internal rotation, and talar tilt without restricting subtalar joint motion. CLINICAL RELEVANCE: We found considerable mechanical differences among the more commonly performed lateral ankle reconstructions. It is possible to locate bone tunnels and graft placement so that a more anatomic configuration is achieved.

Low conductivity irrigating solutions for arthroscopy.

The purpose of this study was to find a nonconductive physiologic solution to use for arthroscopy when electrosurgery is performed. We studied the effect of several solutions on proteoglycan synthesis in bovine articular cartilage slices, and the effect of using an electrosurgical instrument in various solutions in bovine knee joints. Both HEPES buffer 0.3 M (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) (Sigma Chemical Company, St. Louis, Missouri) and glycerol 2.6% gave good results in both categories. The glycerol solution appears to be the best from those tested since it supported cartilage metabolism somewhat better and is far less expensive than HEPES solution. Thus, in the use of electrosurgery during arthroscopic procedures, solutions such as Ringer's lactate and saline are too conductive to be effective or safe. Distilled water is nonphysiologic. Glycerol 2.6% is safe and effective and supports articular cartilage metabolism reasonably well for up to 2 h.

Measurement of anterior-posterior displacement of the knee. A comparison of the results with instrumented devices and with clinical examination.

Thirteen subjects who had normal knees and fifteen patients who had a chronic rupture of the anterior cruciate ligament were tested in order to compare the measurements of tibiofemoral displacement as recorded by four commercial devices: the Acufex knee-signature system, the Genucom knee-analysis system, the Medmetric KT-1000 arthrometer, and the Stryker knee-laxity tester. Anterior and posterior displacement were measured at forces of eighty-nine newtons (twenty pounds) and 133 newtons (thirty pounds). We found significant differences in reproducibility of measurement among the devices. The Acufex, Medmetric, and Stryker devices had more reproducible measurements, and they could be used to identify 80 to 90 per cent of the normal subjects and anterior cruciate-deficient patients. The Genucom device had poorer reproducibility of measurement, and it tended to register greater differences in displacement between the right and left knees of normal subjects.

Histological studies of the glenoid labrum from fetal life to old age.

To help to resolve the controversy regarding the composition of the glenoid labrum, thirty-eight shoulders from cadavera were examined grossly and histologically. We used specimens for individuals of different ages so that we could determine what changes occur as a result of aging. In children and adults, the labrum appeared to be fibrocartilaginous tissue. The labrum was a separate anatomical structure that could be distinguished from the fibrous capsule of the shoulder. Neonatal labra were composed of primitive mesenchymal tissue containing only few chondrocytes that modulated into fibrocartilage in the first few years of life. Neonatal labra contained no elastin, whereas specimens from adults had rare elastin fibers. The labrum was sparsely vascularized throughout its substance, with no particular pattern of distribution. Vascularity decreased with increasing age of the individual.

Strain measurement in lateral ankle ligaments.

We measured strain in the lateral ligaments of 10 human cadaver ankles while moving the ankle joint and applying stress in a variety of ways. We studied the anterior talofibular, calcaneofibular, posterior talofibular, anterior tibiofibular, and posterior tibiofibular ligaments. Strain measurements in the ligaments were recorded continuously while the ankle was moved from dorsiflexion into plantar flexion. We then repeated measurements while applying inversion, eversion, internal rotation, and external rotation forces. Strain in the anterior talofibular ligament increased when the ankle was moved into greater degrees of plantar flexion, internal rotation, and inversion. Strain in the calcaneofibular ligament increased as the talus was dorsiflexed and inverted. These findings support the concept that the anterior talofibular and calcaneofibular ligaments function together at all positions of ankle flexion to provide lateral ankle stability. We measured maximum strain in the posterior talofibular ligament when the ankle was dorsiflexed and externally rotated. The strain in the anterior and posterior tibiofibular ligaments increased when the ankle was dorsiflexed. External rotation increased strain in the anterior tibiofibular ligament and decreased strain in the posterior tibiofibular ligament. Based upon strain measurements in the lateral ankle ligaments in various ankle joint positions, we believe the anterior talofibular ligament is most likely to tear if the ankle is inverted in plantar flexion and internally rotated. Theoretically, the calcaneofibular ligament tears primarily in inversion if the ankle is dorsiflexed; the anterior tibiofibular ligament tears in dorsiflexion, especially if combined with external rotation; and the posterior tibiofibular ligament tears with extreme dorsiflexion.

Knee injuries in sports.

Many knee injuries that previously caused disability can now be diagnosed accurately and treated successfully. Arthroscopy has been instrumental in this progress. The anterior cruciate ligament, which is an important stabilizer of the knee, is commonly injured. Disruption of the restraint provided by the ligament results in an unstable knee that can give way during pivoting motions. Early reconstruction is usually effective in restoring stability and improving function. Considerable progress has been made in knee bracing. However, prophylactic bracing has not been demonstrated to be effective in preventing knee injuries.