Volume 18-2, Summer 2009

Traumatic glenohumeral instability represents a commonly encountered clinical scenario. Two case vignettes are presented along with an evidence-based review of epidemiology, pathophysiology, diagnosis, and treatment options. (Journal of Surgical Orthopaedic Advances 18(2):59–68, 2009) Key words: athlete, diagnosis, traumatic glenohumeral instability, traumatic shoulder instability, treatment

Argon beam coagulation (ABC) has been advocated as adjuvant treatment after curettage of aggressive benign bone tumors. This study was done to evaluate the depth of necrosis in cancellous bone treated with ABC. A 6-month-old pig was sacrificed and 20 1.5-cm cortical windows were created in the metaphyseal areas of the humeri, femora, and tibiae, exposing the underlying cancellous bone. The defects were randomly assigned to four groups: A, control; B, ABC at 50 W; C, 100 W; and D, 150 W. Histologic evaluation determined the depth of necrosis at each setting: A, 0.1 š 0.1 mm; B, 1.0 š 0.5 mm; C, 2.9 š 1.0 mm; and D, 4.2 š 0.7 mm. There were statistically significant differences between each of the experimental groups and the control (p < .0001), between groups B and C (p < .0001), and groups C and D (p D .0002). (Journal of Surgical Orthopaedic Advances 18(2):69–73, 2009) Key words: animal study, argon beam coagulation, bone tumor curettage, histologic evaluation

There are relatively few data on the indications for revision total knee arthroplasty. The purpose of this study was to determine if the indications for revision have changed over the past decade. This is a retrospective review of demographic data and the indications for revision in two cohorts of patients by one surgeon. Patient gender, age, weight, time in situ, and reason for revision (eight categories) were recorded and analyzed by unpaired t-tests and chi-square tests. The first cohort was 81 revisions performed between 1990 and 1999. The second cohort was 116 revisions performed between 2000 and April 2008. There were no significant differences in the gender, mean age, mean weight, or mean time in situ between the two cohorts. There were more revisions for wear (p D .03) and instability (p D .06) in the recent cohort. There were significantly fewer revisions related to the patella prosthesis (p < .0001). There was no change in the number of revisions for infection between the two cohorts. The relative indications for revision total knee arthroplasty have changed over the past decade. Greater emphasis may be needed on improved balancing techniques to prevent instability and new bearing surfaces to decrease wear. (Journal of Surgical Orthopaedic Advances 18(2):74–76, 2009) Key words: revision, total knee arthroplasty

Posterior lumbar interbody fusion (PLIF) using interbody cages and posterior pedicle screw fixation has increased the successful fusion rate to nearly 100% in the lumbar spine. In the design of the cage, only the surface area of the opening for bone graft contact with the endplates varied with the width of the cage. When space is limited, the 9-mm width cages may be the largest size that can be used. Fusion is potentially compromised by the smaller surface area of bone graft. It is important to study the clinical and fusion success of these narrow cages. The authors report 90 patients who had PLIF with 9-mm Lumbar I/F Cages and pedicle screws. Minimum follow-up was 24 months (range, 2–5 years). Seventy-five patients (83%) had clinical success, and 15 (17%) were clinically unsuccessful. Fusion was successful in 82 patients (91.1%). Fusion success with the 9-mm cage was statistically lower than previously reported for the implant system as a whole (p D .0015). Mechanical failure did not occur with 9-mm cage usage. (Journal of Surgical Orthopaedic Advances 18(2):77–82, 2009) Key words: cage, degenerative disc disease, interbody fusion orthosis, intervertebral disk/pathology/

Postoperative stiffness or instability may result from a total knee arthroplasty imbalanced in the sagittal plane. Total knee arthroplasty instrumentation systems differ in the basic strategies used to assure this balance. In an anterior referencing system, changes in femoral size affect flexion gap tightness, and femoral size selection is paramount to assure sagittal plane balance. Conversely, in posterior referencing systems, femoral size changes do not affect the flexion gap but, rather, influence femoral component–patella articulation. Flexion/extension gap systems use calibrated spacer blocks to ensure gap balance but do not guarantee midrange stability; if used incorrectly, they may cause component malposition and joint line elevation. The authors reviewed the strengths and weaknesses of system types and provided system-specific troubleshooting guidelines for clinicians addressing intraoperative sagittal plane imbalance. (Journal of Surgical Orthopaedic Advances 18(2):83–92, 2009) Key words: anterior referencing system, guidelines, posterior referencing system, sagittal plane balance, total knee arthroplasty

Unplanned surgical excision of sarcomas remains a major treatment dilemma in the control of local disease. The purpose of this study is to develop a patient profile to identify patients at high risk for an unplanned excision. The study group consisted of 54 patients following an unplanned excision of a soft tissue sarcoma. The characteristics that were identified as high risk included the following: 20- to 40-year age range,>5 cm, trauma, and deep to fascia. It was common for the interpretation of imaging studies not to mention the possibility of sarcoma in the differential diagnosis. Patient referral was most commonly from general surgeons without specialty training in oncology. Orthopaedic surgeons should not rely solely on the radiologist’s interpretation because they often lack clinical information necessary to direct them toward the diagnosis of sarcoma. This is particularly important in patients who are at high risk for unplanned excision as identified in this study. Unplanned excisions by nononcologic surgeons remain a problem; however, it appears that it is more prevalent in the general surgical community than in orthopaedics. This may be as a result of studies addressing this issue in orthopaedic journals, with emphasis of these articles at teaching institutions. (Journal of Surgical Orthopaedic Advances 18(2):93–98, 2009) Key words: complications, excisional biopsy, metastasis, recurrence, resection, sarcoma

Immediate full weightbearing after total hip arthroplasty can potentially lead to faster recovery. This cadaver study demonstrated that a proximally coated taper stem and a fully porous coated cylindrical stem did not differ in axial and torsional stability at failure under simulated full weightbearing with force directed both along the stem axis and perpendicular to the plane of the prosthesis. Both the taper stem and the cylindrical stem showed adequate stability for an immediate weightbearing protocol with respect to gross failure in osteoporotic bone. (Journal of Surgical Orthopaedic Advances 18(2):99–102, 2009) Key words: arthroplasty, hip prosthesis, weightbearing

The purpose of this case report is to present an unusual fracture pattern in an 11-year-old patient characterized by both a predominantly adult fracture type and an exclusively adolescent fracture type. The patient sustained a bimalleolar ankle fracture while sledding. A difficult to detect Tillaux fracture was discovered on preoperative radiograph. The fractures were operatively treated by open reduction and internal fixation. The fracture mechanism is most likely attributed to supination–external rotation injury. The patient thus far has no sign of permanent deformity or disability. This case is unique in that it illustrates an adult fracture type in an adolescent patient. The nearly hidden Tillaux fracture also emphasizes the importance of thorough radiographic examination of any fracture. (Journal of Surgical Orthopaedic Advances 18(2):103–105, 2009) Key words: ankle, bimalleolar fracture, Tillaux fracture

One hundred ninety-six patients with Dupuytren’s contractures were treated by partial fasciectomy and adequate postoperative rehabilitation. All patients had flexion contracture of the proximal interphalangeal joint of >20°; 93 patients had flexion contracture of the associated metacarpophalangeal joint of >30°; 143 patients had risk factors for Dupuytren’s disease. Primary skin closure and splinting were done in all patients. Range of motion was begun by the 1st week. Splinting was discontinued by the 2nd week, followed by night-time splinting until the 8th week. The mean follow-up was 6.6 years (range, 2–9 years). At the latest examination, 72.5% of the patients had complete range of motion of the metacarpophalangeal and proximal interphalangeal joints; 20.2% had 5° –10° of extension deficit and 7.3% had recurrent contractures of >20° at the proximal interphalangeal joint and were subjected to reoperation. Complications included digital neurovascular injury in 5%, complex regional pain syndrome in 10.1%, and wound-healing problems and superficial infections in 15.1%. (Journal of Surgical Orthopaedic Advances 18(2):106–110, 2009) Key words: cords, Dupuytren’s disease, fasciectomy, metacarpophalangeal joint, nodules, proximal interphalangeal joint