Kyung-Cheon Kim

Influence of femoroacetabular impingement on results of hip arthroscopy in patients with early osteoarthritis.

To ascertain whether better results could be obtained using hip arthroscopy, we retrospectively reviewed the radiographic and clinical aspects of anterior femoroacetabular impingement in 43 patients diagnosed with early osteoarthritis with acetabular labral tears who previously had arthroscopic treatment. The average followup was 50 months. The patients were divided into two groups: patients who had no osteoarthritis seen on simple radiographs, but had degenerative changes of the labrum and cartilage seen on magnetic resonance arthrograms and arthroscopy, and patients who had osteoarthritic findings seen on simple radiographs. Both groups were examined retrospectively for signs of anterior femoroacetabular impingement at the acetabulum and proximal femur. Postoperative improvement was evaluated using the Japanese Orthopaedic Association pain score. Six of 21 patients in Group I and 12 of 22 of patients in Group II showed radiographic evidence of femoroacetabular impingement. The score improved from 0.76 preoperatively to 2.38 postoperatively in Group I and from 0.75 preoperatively to 1.90 postoperatively in Group II. Arthroscopic débridement produced improved results seen during short-term and midterm followups. However, in patients with femoroacetabular impingement the results were considered inadequate. We found that arthroscopic treatment of osteoarthritis of the hip fails if there is detectable femoroacetabular impingement.Level of Evidence: Level IV, retrospective case series. See the Guidelines for Authors for a complete description of levels of evidence.

Arthroscopic fixation for displaced greater tuberosity fracture using the suture-bridge technique.

With the described technique, two bioabsorbable suture anchors are inserted to create a medial row through the intact cuff for fixation of the fragment of the greater tuberosity. The medial row is repaired with a sliding knot. After confirmation of the fracture site, pilot holes for a PushLock anchor (Arthrex, Naples, FL) are prepared directly in line with the medial anchors and approximately 5 to 10 mm distal to the lateral edge of the fragment of the greater tuberosity. A suture strand from each anchor in the medial row is retrieved. Both suture strands are threaded through the PushLock eyelet on the distal end of the driver. The anchor is advanced completely into the pilot hole. These steps are repeated for a second anchor. If a dog-ear deformity is observed at the margin after complete reduction of the greater tuberosity, a stitch is made by use of a suture hook and one strand of the uncut suture from the lateral row of the joint via the modified suture-bridge technique. Arthroscopic reduction and internal fixation of displaced greater tuberosity fractures with the suture-bridge technique described by us provide adequate fixation with improvement of the pressurized contact area of the fracture and can be used as an additional modality of arthroscopic treatment.

Estimating the dimensions of the rotator interval with use of magnetic resonance arthrography

BACKGROUND The goal of the present study was to define the dimensions of the normal rotator interval with magnetic resonance arthrography and to compare these dimensions with those in shoulders with known chronic anterior instability in order to determine if abnormalities of the rotator interval might be better understood and estimated preoperatively. METHODS We retrospectively reviewed a consecutive series of 202 shoulders that had undergone magnetic resonance arthrography between 2004 and 2005. Of these, 120 shoulders were included in the present study. These shoulders were divided into two groups according to the diagnosis. Group I comprised fifty shoulders with no instability, and Group II comprised seventy shoulders with chronic anterior instability. With use of magnetic resonance arthrography, the base and height of the rotator interval and the diameter of the glenoid were measured. Then, the area of the rotator interval and the rotator interval index were calculated. RESULTS In Group I, the mean estimated rotator interval dimensions (height and base), the mean calculated rotator interval area, and the mean rotation interval index were 16.73 mm, 48.59 mm, 406.47 mm(2), and 0.64, respectively. In Group II, these values were 21.87 mm, 49.40 mm, 540.06 mm(2), and 0.94, respectively. The shoulders in Group II differed significantly from the shoulders in Group I in terms of rotator interval height, rotator interval area, and rotator interval index (p < 0.01 for all). CONCLUSIONS There are significant differences in the dimensions of the rotator interval between patients with and without recurrent anterior shoulder instability. Estimating the dimensions of the rotator interval with use of magnetic resonance arthrography may be valuable for assessing patients preoperatively.

Can the Glenopolar Angle be Used to Predict Outcome and Treatment of the Floating Shoulder

OBJECTIVE Displaced ipsilateral fractures of the clavicle and the glenoid neck are usually the result of high-energy trauma. The objective of this study is to evaluate the association of the glenopolar angle (GPA) with the clinical outcome of the floating shoulders. METHODS Seven patients treated conservatively and nine patients with clavicular fracture treated operatively were evaluated retrospectively. The GPA of the affected (a-GPA) and unaffected (u-GPA) shoulders, and the change (d-GPA) were measured. The Constant-Murley score of the affected (a-CS) and unaffected (u-CS) shoulders, and the change (d-CS) were measured at the last follow-up. RESULTS The mean follow-up was 25 months, and the score was 69.7 points. Patient age had no effect on the clinical outcome, and the change in GPA in the affected shoulder between the initial and last follow-up for the nonoperated and operated groups did not differ statistically (p > 0.05). There were positive correlations between a-CS and a-GPA (r = 0.760, p < 0.05) and between d-GPA and d-CS (r = 0.643, p < 0.05) and negative correlations between a-GPA and d-CS (r = -0.962, p < 0.05) and between d-GPA and a-CS (r = -0.703, p < 0.05). CONCLUSION The simple measurement of GPA may yield useful prognostic information and help in making decisions concerning the floating shoulder.

Displaced fracture of the coracoid process associated with acromioclavicular dislocation: a two-bird-one-stone solution.

We describe a surgical treatment for a displaced fracture of the coracoid process associated with acromioclavicular dislocation. This treatment involves fixing the coracoid process using a cannulated screw without acromioclavicular fixation under fluoroscopic guidance. The benefits of this treatment are that fixation with a cannulated screw simultaneously reduces both the displaced fracture of the coracoid process and the acromioclavicular joint via the intact coracoclavicular ligament, thus reducing the complications associated with transacromial pin fixation.

Deformities Associated With the Suture-Bridge Technique for Full-Thickness Rotator Cuff Tears

PURPOSE This study was performed to evaluate the incidence and cause of deformities associated with the suture-bridge technique in rotator cuff tears. METHODS We performed a prospective review of a consecutive series of 100 shoulders with full-thickness tears (50 with medium tears, 43 with large tears, and 7 with massive tears) treated by use of the suture-bridge technique in 2007. The surgical technique was classified according to the number of suture anchors inserted in the medial and lateral rows (2 x 2 suture bridges in 82 cases, 3 x 2 in 12, and 3 x 3 in 6). On arthroscopy, the development of a marginal dog-ear deformity and central bird-beak deformity during the repair was investigated. These deformities were corrected by use of the modified suture-bridge technique or by insertion of an additional suture anchor. RESULTS Dog-ear deformities occurred in 47 cases and were most frequent in large tears treated with a 2 x 2 suture bridge (21 cases). Dog-ear deformities in 2 x 2 suture bridges were more frequent in large tears than in medium tears (P < .05), and with large tears, they were more frequent with 2 x 2 suture bridges than with 3 x 2 suture bridges (P < .05). Bird-beak deformities occurred in 13 cases and were most frequent in large tears treated with 2 x 2 suture bridges (9 cases). Bird-beak deformities with 2 x 2 suture bridges were more frequent in large tears than in medium tears (P < .05), and with large tears, they were more frequent with 2 x 2 suture bridges than with 3 x 2 suture bridges (P < .05). CONCLUSIONS To reduce deformities associated with the suture-bridge technique during rotator cuff repair, individualized repair methods may be applied according to the size and pattern of the rotator cuff tear. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Provisional Unicortical Plating With Reamed Intramedullary Nailing in Segmental Tibial Fractures Involving the High Proximal Metaphysis

This simple procedure for treating segmental tibial fractures involving the high proximal petaphysis decrease complications such as malalignement, nonunion, and postoperative infection by avoiding latrogenic devascularization of the fracture site.

Spin disorder scattering mechanism of ferromagnetic Ga1-xMnxAs layers on (100) GaAs substrates

The temperature-dependent Hall resistivity and carrier concentrations of Ga1−xMnxAs epilayers grown on (100) semi-insulating GaAs substrates by molecular beam epitaxy have been investigated in the temperature range of 10–300 K. A Ga1−xMnxAs sample with x≈4.4% shows typical insulator behavior and Ga1−xMnxAs samples with x≈2.2 and 3.7 % show typical metallic behavior. A model taking into account ionized impurity and spin disorder scattering mechanisms was used to portray properly the observed features of the temperature-dependent Hall resistivity data. The value of the p-d exchange energy was J=59.4±0.5 and 71.9±0.5 eV A3 for the samples with x≈2.2 and 3.7 %, respectively. Ionized impurity scattering dominates the entire temperature range, with a temperature-independent spin disorder scattering in the paramagnetic region. It was found that the spin disorder scattering mechanism had a strong temperature dependence on 1−T2 in the ferromagnetic region.

Flexible intramedullary nailing in simple bone cysts of the proximal humerus: prospective study for high-risk cases of pathologic fracture.

We designed and evaluated a modified cyst index using the Picture Archiving and Communication System software for treating simple bone cysts of the proximal humerus by preventive intramedullary flexible nail insertion in symptomatic children or adolescents. From January 2007 to December 2009, cases with a cyst index of at least 4 were enrolled in the study. Of 20 total cases, 19 were prospectively followed-up for at least 2 years. The mean patient age was 10.6 years (range, 7–15 years) and the mean modified cyst index was 6.56 (range, 4.95–8.25). The mean cyst healing period was 8.7 months (range, 4–30 months) and the mean follow-up period was 31.05 months (range, 24–42 months). Seventeen lesions (89%) were classified as completely healed and two (11%) were classified as healed with residual radiolucency. In all cases, no angular deformity was found on the final follow-up radiograph. Therefore, preventive flexible intramedullary nail insertion before the occurrence of a pathologic fracture because of simple bone cysts with a modified cyst index of at least 4 in the proximal humerus is an excellent treatment option. Level of Evidence: Therapeutic Level IV.

Tension Band Sutures Using a Washer for a Proximal Humerus Fracture

To prevent distraction and varus deformity between the humeral head and shaft, tension band sutures placed between the head of the interlocking screw and the rotator cuff, and we recommend using nonabsorbable sutures. We describe our simple procedure to overcome these difficulties in tension band suturing after reducing a proximal humerus fracture to maintain the reduction.