Effects of back support on intra-abdominal pressure and lumbar kinetics during heavy lifting.

Lumbosacral supports (LSSs) have been used to minimize the risk of lower back injuries. Theoretically, an LSS will raise intra-abdominal pressure (IAP) and reduce loads in the lower back region. This investigation compared three different LSSs with an unsupported condition. Nine males lifted a weighted box four times, once per condition, at 90% of their one-repetition maximum. Conditions were compared in terms of effects on IAP and its relieving force on L5-S1 kinetics. A multivariate analysis of covariance revealed no statistically significant differences among the three LSSs and the nonsupport conditions on the aforementioned dependent variables. This suggests that there is no difference among LSSs in terms of their biomechanical effects on the lower back region and that the use of any LSS does not necessarily afford more protection than a proper lift without one.

Varus tension testing of fixation devices used in proximal tibial osteotomy.

Varus tension testing was performed on 26 matched pairs of tibias after high tibial osteotomy with three different fixation techniques--Coventry stepped staple, Mansat staple blade, and modified tension-band. Biomechanical testing revealed that in group I the Coventry stepped staple and Mansat staple blade yielded similar force at failure values of 132.44 +/- 29.29 and 137.34 +/- 40.84, respectively. In group II, the varus force at failure value was 170.45 +/- 83.95 for the modified tension band device versus 115.27 +/- 67.21 for the Coventry stepped staple device. In group III, the varus force at failure value was 180.26 +/- 82.36 for the modified tension band device versus 109.14 +/- 60.96 for the Mansat staple blade. The findings in this study suggest that the modified tension band technique provides a greater varus force at failure value, approximately 160-170%, compared to the other two techniques. In addition, this device is easy to apply and less expensive, and most orthopaedic surgeons are already familiar with its use.

A modified internal rotation stretching technique for overhand and throwing athletes.

Strength, stretching, and rehabilitation methods for the shoulder have been previously described and have been universally applied; nevertheless, many throwing athletes continue to develop overuse injuries. The pitching process tends to increase external rotation and limit internal rotation of the shoulder joint. Our technique involves a modified stretching method of the posterior shoulder musculature. The athlete lies prone with the elbow flexed 90 degrees. With the shoulder abducted 90 degrees, in neutral flexion/extension, and 90 degrees or more of internal rotation, the scapula protrudes posteriorly. By depressing the inferior angle of the scapula toward the thoracic wall, the infraspinatus muscle and posterior joint capsule are effectively isolated and stretched. Manual stabilization of the scapula onto the chest wall transfers the internal rotation movements to the glenohumeral joint, as opposed to sharing the movement with the scapulothoracic articulation. This method improves the efficacy of the internal rotation stretching exercise for the glenohumeral joint. Such an addition to traditional stretching methods may increase the efficiency of the least effective component. We conclude that this modification to traditional programs should be an integral part of the training and rehabilitation program of any athlete requiring near maximal performance of the shoulder.

Soft tissue reconstruction in the shoulder. Comparison of suture anchors, absorbable staples, and absorbable tacks.

We evaluated three mechanical soft tissue fixation devices (SuperAnchor, Suretac, and the Instrument Makar [IM] Bioabsorbable Staple) in a cadaveric model by examining ultimate tensile failure and modes of failure in simulated Bankart repairs. We attempted to realistically evaluate the strengths of soft tissue reattachment procedures at the anterior glenoid under worst-case conditions--load to failure. Twenty fresh-frozen cadaveric shoulders were used in this investigation. Each of the three techniques was performed in each anterior glenoid rim at one of three locations: superior, middle, or inferior. The subscapularis muscle-tendon was harvested, used in the repair, and loaded to failure. The mean load at failure for the SuperAnchor was 217.32 N; for the IM Staple, 132.32 N; and for the Suretac, 122.37 N. A two-sample t-test demonstrated that the load at failure for the SuperAnchor was statistically greater (P < 0.001) when compared with the IM Staple and Suretac. There was no statistical difference between load at failure for the Suretac and the IM Staple. The most common failure mode for the Mitek was suture breakage (71%). Anchor pullout from bone was the most common failure mode for the IM Staple (75%) and Suretac (94%).

Fluoroscopic evaluation for subtle shoulder instability.

Fifty patients with unilateral shoulder symptoms and a variety of diagnoses were evaluated with stress testing of both shoulders under general anesthesia using fluoroscopic documentation just before surgery. An axillary lateral view of the glenohumeral joint was taken in neutral rotation and 90 degrees of abduction; this was termed "neutral position." Anterior and posterior translational stresses were then applied and spot radiographs taken. Measurements were made and the translation was expressed as a percentage of displacement of the humeral head with respect to the glenoid. The asymptomatic side was used as a control. We determined that up to 14% anterior translation and up to 37% posterior translation is normal. Using these guidelines, attempts were made to confirm or predict the presence of stability or instability. Thirty-one patients were correctly identified as stable; 14 were correctly identified as unstable. Three patients with anterior shoulder pain were classified as unstable and found to have Bankart lesions at surgery. Overall, specificity was 100% and sensitivity was 93%. Using discriminant function analysis, a difference score of 10% between the symptomatic and control shoulder was generated. This was useful in eliminating interobserver variations in the examination for predicting stability or instability. We recommend this examination as a valuable adjunct to confirm the presence and direction of shoulder instability and predict subtle instability patterns in patients with recalcitrant undiagnosed shoulder pain.

Arthroscopic release of a posttraumatic flexion contracture in the elbow: a case report and review of the literature.

Open arthrotomy has been the standard of treatment for posttraumatic flexion contractures of the elbow. Utilizing standard arthroscopic techniques combined with electrocautery, anterior capsulotomy was performed without complication. Immediate improvement in extension was demonstrated. Multiple cadaveric dissections evidenced the safety of the approach as the humeral capsular attachment is isolated from the neurovascular structures by the brachialis muscle. This technique serves to underscore the utility of elbow arthroscopy in patients with dysfunction previously only amenable to open joint procedures.

Femoral instrumentation using the anterosuperior iliac spine as a landmark in total knee arthroplasty. An anatomic study.

Twenty-six adult cadavers were utilized in an anatomic study designed to measure intramedullary femoral alignment in relation to the anterosuperior iliac spine. Fifty femurs were measured to determine the reliability of the anterosuperior iliac spine as an accurate landmark for distal femoral resection in total knee arthroplasty (TKA). A precision machined stainless steel U-shaped parallel alignment guide was fabricated and inserted into the femoral canals of intact adult cadavers. The guide's relationship to the anterosuperior iliac spine was measured and recorded. All hips were maintained in neutral alignment. Independent variables recorded included gender, knee alignment, and side of lower extremity. The range for medial deviation was 1-28 mm for the right femur and 2-25 mm for the left femur (average, 8.5 mm). The range for lateral deviation was 3-14 mm for the right femur and 2-17 mm for the left femur (average, 10.3 mm). There was no statistical correlation between the independent variables of side measured, gender, and measured offset at the anterosuperior iliac spine. Based on this highly variable pattern of alignment, utilizing simulated intraoperative technique, use of the anterosuperior iliac spine does not provide a landmark accurate enough to repeatedly produce a distal femoral resection within 2 degrees-3 degrees of ideal. Use of the anterosuperior iliac spine may lead to less than ideal femoral resection and malpositioning of total knee components.

Thermal injury resulting from arthroscopic lateral retinacular release by electrocautery: report of three cases and a review of the literature.

This article reports three cases of full-thickness thermal burns of the skin in the 85 cases of arthroscopic lateral retinacular release we performed using electrocautery. To our knowledge, this complication has not previously been reported.

Effect of inosine supplementation on 3-mile treadmill run performance and VO2 peak.

The purpose of this study was to investigate the ergogenic effect of oral inosine (IN) supplementation (6,000 mg.d-1 for 2 d) upon 3-mile run time (3MTIME) and VO2 peak. Nine highly trained endurance runners participated in a double-blind, placebo (PL), crossover study. Each subject undertook an IN or PL trial, consisting of three exercise tests: a submaximal warm-up run (SUBRUN), a competitive 3-mile treadmill run (3MRUN), and a maximal treadmill run (MAXRUN) to determine VO2 peak and time to exhaustion (MAXTIME). Additional measurements during the 3MRUN and MAXRUN included oxygen uptake (VO2), ventilation (VE), respiratory exchange ratio (R), and ratings of perceived exertion (RPE); blood samples were also taken prior (PRERUN) to the SUBRUN test and following the SUBRUN, 3MRUN, and MAXRUN tests in order to assess glucose, pyruvate, lactate, phosphorus, 2,3-DPG, hemoglobin, and uric acid. Analyses of the data revealed no significant effect of oral IN supplementation either upon 3MTIME (IN = 18.31 +/- 1.21; PL = 18.33 +/- 1.15 min) or VO2 peak (IN = 58.6 +/- 5.1; PL = 60.7 +/- 4.5 ml O2.kg-1.min-1) or upon other dependent variables. MAXTIME was significantly longer during the PL trial (P less than 0.05), suggestive of a possible impairment effect of oral IN supplementation. Based upon our data, we conclude that IN is not an effective ergogenic aid to enhance athletic performance of an aerobic nature.

Selected isokinetic lifting parameters of adult male athletes utilizing lumbar/sacral supports.

This work was supported by Sentara Leigh Hospital, Physical Therapy Special Center, Norfolk, VA. The present investigation isokinetically evaluated the effects of two lumbar/sacral supports (LSS) upon peak lifting force, total muscular work, and average muscular power. Subjects consisted of 10, well conditioned male athletes with an age range of 21-35 years. Subjects were required to perform three counterbalanced testing sessions separated by a 7 day rest interval. Three lifting speeds (60.96, 76.2, and 91.44 cm/sec) were selected in accordance with a standard Cybex Liftask(R) protocol. No statistically significant (p < 0.05) isokinetic effects were recorded. Comparative grand means, however, demonstrated slight increases for peak lifting force and average muscular power (76.2 cm/sec) when subjects were assigned a LSS. Results may suggest functional lifting qualities attributed to utilizing a LSS while performing maximal lifting tasks. J Orthop Sports Phys Ther 1990;11(10):467-473.

Compression neuropathy of the radial nerve as a complication of elbow arthroscopy: a case report and review of the literature.

Arthroscopic surgery of the elbow was performed in a 14-year-old male athlete for diagnosis and treatment of osteochondritis dissecans of the capitellum. Anterolateral and anteromedial portals were used in accordance with described technique. Postsurgical examination revealed an immediate and complete palsy of the posterior interosseous nerve. This complication was attributed to the manipulation of the arthroscope and instrumentation in close proximity to the radial nerve. Neuromuscular function returned to normal over a 6-month period. This case demonstrates the importance of portal placement and instrument manipulation in arthroscopic evaluation and treatment of the elbow. Further study is necessary to develop technical and procedural improvements to assure safe and effective arthroscopic treatment.

The free synovial graft as a shield for collagen ingrowth in cruciate ligament repair.

The anterior cruciate ligament (ACL) was excised bilaterally in the knee joint of three dogs and was replaced in a conventional manner with a composite polyglycolic acid (PGA) and Dacron braided ligament prosthesis. In one knee of each dog, the ligaments were wrapped with a free synovial graft taken from the suprapatellar pouch in an attempt to keep the prosthesis extrasynovial, while the ligaments in the opposite three knees were left uncovered and thus directly exposed to synovial fluid. The dogs were killed at approximately one year postoperation, and microscopic sections of all ligaments were taken. The three knees with the synovial sheath showed a significantly greater bulk of fibrous tissue along the ligament scaffold grossly and a greater abundance of collagen producing cells microscopically, compared to the unwrapped ligaments. The gross and microscopic findings were identical in each of the three knees with the covered ligaments and were equally consistent in the three that had been left unprotected from the synovial fluid. These findings suggest that a free synovial graft may simulate the normal protective role of the synovial membrane and allow and/or induce collagen ingrowth in synthetic or autogeneic tissue stints for the repair of acute cruciate ligament tears.