BACKGROUND

AND

HYPOTHESIS:

Arthroscopic rotator cuff repair can be a painful outpatient procedure. The purpose of this study was to evaluate the efficacy of continuous subacromial bupivacaine infusion to relieve pain after arthroscopic rotator cuff repair. We hypothesized that patients receiving continuous subacromial bupivacaine infusions after arthroscopic rotator cuff repair will have less postoperative pain in the early postoperative period than placebo and control groups.

MATERIALS AND METHODS:

Eighty-eight patients undergoing arthroscopic rotator cuff repair were randomized in a blinded fashion into 1 of 3 groups. Group 1 received no postoperative subacromial infusion catheter. Group 2 received a postoperative subacromial infusion catheter filled with saline solution. Group 3 received a postoperative subacromial infusion catheter filled with 0.5% bupivacaine without epinephrine. Infusion catheters were scheduled to infuse at 4 mL/h for 50 hours. Postoperative pain levels were assessed with visual analog scale scores hourly for the first 6 postoperative hours, every 6 hours for the next 2 days, and then every 12 hours for the next 3 days. Patients recorded daily oxycodone consumption for the first 5 postoperative days.

RESULTS:

Immediately postoperative, the group with no catheter had significantly lower visual analog scale scores (P = .04). There were no significant differences in visual analog scale scores among the groups at any other time point. There were no differences found among the groups regarding mean daily oxycodone consumption.

CONCLUSION:

The use of continuous bupivacaine subacromial infusion catheters resulted in no detectable pain reduction after arthroscopic rotator cuff repair based on visual analog scale scores and narcotic medication consumption.

BACKGROUND:

The ulnar component of a total elbow replacement can fail by "pistoning." Stem surface treatments have improved stability at the stem-cement interface but with varied success. This study investigated the role of surface treatment and stem substrate material on implant stability under axial loading.

MATERIALS AND METHODS:

Sixty circular stems (diameter, 8 mm) made of cobalt chrome (n = 30) or titanium (n = 30) had different surfaces: smooth, sintered beads, and plasma spray. The surface treatment length was either 10 mm or 20 mm. Stems were potted in bone cement, allowed to cure for 24 hours, and tested in a materials testing machine under a compressive staircase loading protocol. Failure was defined as 2 mm of push-out or completion of the protocol. Two-way analyses of variance compared the effects of surface treatment and substrate material on interface strength and motion.

RESULTS:

Significant interactions were found between surface treatment and substrate material for both interface strength and motion (P < .05). For titanium, the 20-mm beaded stems had greater interface strength than all other stems (P < .05) and had less motion than the 10-mm plasma-spray and smooth stems (P < .05). For cobalt chrome, the 20-mm beaded stems showed greater interface strength (P < .05) and similar motion (P > .05) to the 20-mm plasma-spray stems (P < .05), which outperformed all other stems (P < .05). Mechanisms of catastrophic failure varied: smooth stems debonded at the stem-cement interface, beaded stems experienced debonding of the beads from the stem, and plasma-spray stems showed loss of frictional force between the surface treatment and cement.

DISCUSSION AND CONCLUSION:

Stem surface treatment can enhance ulnar component stability but is dependent on substrate material.

BACKGROUND:

Superior glenoid wear is a common challenge with reverse shoulder arthroplasty and, if left uncorrected, can result in superior glenoid tilt, which increases the risk of aseptic glenoid loosening. This study evaluates the impact of an E2 superior defect on reverse shoulder glenoid fixation in composite scapulae after correction of glenoid tilt by use of 2 different glenoid reaming techniques: eccentric reaming and off-axis reaming.

MATERIALS AND METHODS:

A superior glenoid defect was created in 14 composite scapulae. The superior defect was corrected by 2 different glenoid reaming techniques: (1) eccentric reaming with implantation of a standard glenoid baseplate and (2) off-axis reaming with implantation of a superior-augment glenoid baseplate. Each corrected superior-defect scapula was then cyclically loaded (along with a control group consisting of 7 non-worn scapulae) for 10,000 cycles at 750 N; glenoid baseplate displacement was measured for each group to quantify fixation before and after cyclic loading.

RESULTS:

Regardless of the glenoid reaming technique or the glenoid baseplate type, each standard and superior-augment glenoid baseplate remained well fixed in this superior-defect model scenario after cyclic loading. No differences in baseplate displacement were observed either before or after cyclic loading between groups.

DISCUSSION:

Our results suggest that either glenoid reaming technique may be used to achieve fixation in the clinically challenging situation of superior wear with reverse shoulder arthroplasty.

BACKGROUND:

Shoulder stability primarily depends on concavity compression, which relies on the concave shape of the glenoid not mere glenoid width. This study analyzed the effect of anatomic glenoid reconstruction surgery on concavity morphology.

METHODS:

Thirty-one consecutive patients with recurrent anterior shoulder instability and glenoid bone loss underwent surgical stabilization using the J-bone graft. Twenty patients were available for preoperative, postoperative, and 1-year follow-up computed tomography scans. On standardized axial images, the change over time of the glenoid concavity extent, depth, version, and step-formation was measured and compared with the unaffected side.

RESULTS:

The mean preoperative concavity extent was 82.3% and increased (P < .001) after surgery to 113.1% before decreasing (P < .001) to 99.2% at follow-up concordant to the contralateral side (P = .75). The mean concavity depth was 56.6% preoperatively, increased to 226.4% postoperatively (P < .001), and diminished to 149.2% at follow-up (P < .001). Affected glenoids showed an average loss of -6.0° of retroversion preoperatively, with an increase to +5.6° postoperatively (P < .001) and a decrease to +0.2° at follow-up (P < .001). The average step-formation on the articular surface after graft insertion diminished significantly, from 2.3 mm postoperatively to 0.3 mm at follow-up (P < .001).

CONCLUSION:

Anatomic glenoid reconstruction surgery using the J-bone graft provides temporary overcorrection of the glenoid concavity extent, depth, and version, with subsequent normalization due to physiologic remodeling processes.

BACKGROUND:

Entrapment of the suprascapular nerve (SSN) at the spinoglenoid notch (SGN) specifically affects the infraspinatus, and isolated external rotation (ER) weakness can result. We describe the technique of open SSN decompression at the SGN for infraspinatus involvement and report the results of a consecutive series.

MATERIALS AND METHODS:

Twenty-nine shoulders underwent SSN decompression at the SGN. The mean age was 44 years (range, 15-69 years), and the mean follow-up was 4.3 years (range, 1-7 years). On manual muscle testing, ER strength was abnormal in all patients: 2/5 in 3, 3/5 in 21, and 4/5 in 5. The mean preoperative American Shoulder and Elbow Surgeons (ASES) score was 48 (range, 23-83). Atrophy of the infraspinatus was visible or palpable in 72% of shoulders. Magnetic resonance imaging showed ganglion cysts at the SGN in only 20.7% of shoulders.

RESULTS:

Of the patients, 19 (66%) regained full ER strength, 9 (31%) improved to 4/5, and 1 (3%) had ER strength of 3/5. The mean ASES score improved to 75 (range, 60-100) (P < .05). Of 29 shoulders, 23 (79%) showed improved ER strength within 1 week of surgery. All ganglion cyst cases regained full ER strength within a mean of 6 weeks. In all cases, ER strength improved by at least 1 full strength grade.

DISCUSSION:

A ganglion cyst is not necessary to produce SSN compression at the SGN. SSN compression at the SGN can present as an isolated entity or can occur in conjunction with rotator cuff pathology or a ganglion cyst. An index of suspicion, physical examination, magnetic resonance imaging, and electromyography confirm the diagnosis. The described operative approach detaches no muscle and allows rapid recovery, and in all cases, ER strength improved to normal or by 1 full grade.

BACKGROUND:

This study evaluates the long-term results, including complication and revision rates, of different types of total elbow arthroplasty (TEA) with an average follow up of 13 years.

METHODS:

Since 1984, a total of 84 primary TEAs have been performed in 77 patients at our institution. The patient's average age was 54.2 years. We performed unlinked TEA in 35 cases (Pritchard ERS since 1984 [n = 18], Kudo type 3 since 1991 [n = 17]), and semi-linked TEA in 49 cases (Pritchard Mark II since 1997 [n = 14], Coonrad-Morrey since 2001 [n = 35]). We assessed the patients for compliance to daily living guidelines (not to exceed 2.25 kg for repetitive lifting and 4.5 kg for single episode lifting), and followed up with them for an average of 13 years after primary TEA. We analyzed their results with regard to complication and revision rates as the type of TEA.

RESULTS:

The mean Mayo Elbow Performance Score (MEPS) improved from preoperative 34 points to postoperative 84 points. The active flexion-extension elbow motion increased from 25°-94° preoperative to 12°-130° postoperative. The overall complication rate was 44.0% (37/84 cases); the rate was statistically higher in the unlinked group (62.9%, 22/35 cases) than in the semi-linked group (30.6%, 15/49 cases). The overall revision rate was 27.4% (23/84 cases); the rate was higher in the unlinked group (34.3%, 12/35 cases) than in the semi-linked group (22.4%, 11/49 cases).

CONCLUSION:

Semi-linked TEA has better outcomes than unlinked TEA with respect to complication and revision rates; but continuous efforts to develop a new TEA design for longevity, improved cementing technique, and supporting activities of daily living are needed to reduce complication and revision rates in the future.

BACKGROUND:

The goal of this study was to investigate the incidence of a medial bony ridge at the scapular neck in patients with recurrent anterior shoulder instability and analyze its reliability in identifying anterior glenoid rim bone loss.

METHODS:

A total of 109 shoulders in 105 consecutive patients underwent primary surgical stabilization for recurrent anterior shoulder instability with preoperative 2-dimensional and 3-dimensional computed tomography (CT) evaluation. The CT images of each affected shoulder were analyzed for the extent of anterior glenoid bone loss and the presence of a "medial-ridge sign." The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the medial-ridge sign were calculated for different sizes of glenoid rim defects.

RESULTS:

A positive medial-ridge sign was detected in 77.1% of the shoulders. The sensitivity of the medial-ridge sign ranged from 81.6% (95% confidence interval [CI], 73.0%-87.9%) for defects greater than 0% to 100% (95% CI, 82.4%-100%) for defects ≥20%. The PPV of the medial-ridge sign decreased from 100% for defects >0% to 11.9% for defects ≥25%. The specificity of the medial-ridge sign decreased from 100% (95% CI, 61.0-100%) for defects >0%, to 25.3% (95% CI, 17.7%-34.6%) for defects ≥25%. The NPV of the medial-ridge sign increased from 24.0% for defects >0% to 100% for defects >20%.

CONCLUSION:

The medial-ridge sign represents a CT-based radiologic sign with high sensitivity and NPV for identification of significant anterior glenoid rim defects in case of recurrent anterior shoulder instability.

BACKGROUND

AND

HYPOTHESIS:

Rotator cuff tears are the most common injury seen by shoulder surgeons. Glenohumeral osteoarthritis develops in many late-stage rotator cuff tear patients as a result of torn cuff tendons, termed "cuff tear arthropathy." However, the mechanisms of cuff tear arthropathy have not been fully established. It has been hypothesized that a combination of synovial and mechanical factors contribute equally to the development of cuff tear arthropathy. The goal of this study was to assess the utility of this model in investigating cuff tear arthropathy.

MATERIALS AND METHODS:

We used a rat model that accurately reflects rotator cuff muscle degradation after massive rotator cuff tears through either infraspinatus and supraspinatus tenotomy or suprascapular nerve transection. Using a modified Mankin scoring system, we found significant glenohumeral cartilage damage after both rotator cuff tenotomy and suprascapular nerve transection after only 12 weeks.

RESULTS:

Cartilage degeneration was similar between groups and was present on both the humeral head and the glenoid. Denervation of the supraspinatus and infraspinatus muscles without opening the joint capsule caused cartilage degeneration similar to that found in the tendon transection group.

CONCLUSIONS:

Our results suggest that altered mechanical loading after rotator cuff tears is the primary factor in cartilage degeneration after rotator cuff tears. Clinically, understanding the process of cartilage degeneration after rotator cuff injury will help guide treatment decisions in the setting of rotator cuff tears.

BACKGROUND:

Presently, 2 types of elbow prostheses are used: unlinked and linked. The Latitude total elbow prosthesis allows the surgeon to decide during the implantation whether the prosthesis is placed unlinked or linked, and whether the native radial head is retained, resected, or replaced. The purpose of this study is to assess and to compare the varus and valgus laxity of the unlinked and linked version of the latitude total elbow prosthesis with: (1) the native radial head preserved, (2) the native radial head excised, and (3) the native radial head replaced by a radial head component.

METHODS:

Biomechanical testing was performed on 14 fresh-frozen upper limb specimens.

RESULTS:

Linking the prosthesis predominantly influences the valgus laxity of the elbow. DISCUSSION/

CONCLUSION:

Linking the Latitude total elbow prosthesis results in increased valgus stability. In the linked version of the total elbow prosthesis, the radial head only plays a small part in both valgus and varus stability. An unlinked situation is not advised in absence of a native radial head or in case of inability to replace the radial head.