What's new in shoulder and elbow surgery

Focus on stability: biomechanical evaluation of external fixation technique versus locking plate osteosynthesis in 3-part proximal humeral fractures

BACKGROUND

The purpose of this study was to investigate the primary stability and displacement tendencies of an external fixation system in 2 different configurations in comparison to locking plate fixation in a 3-part proximal humeral fracture model.

METHODS

Twenty-one fresh-frozen human cadaveric proximal humeral specimens were divided into 3 groups of 7 stripped specimens. An unstable 3-part fracture of the proximal humerus was set. Construct A consisted of the Galaxy Fixation Shoulder System, with fixation in accordance with the manufacturer's recommended technique (3 pairs of threaded wires). Construct B was fixed with an additional pair of threaded wires according to the recommendations of Gumina et al (4 pairs of threaded wires). The remaining 7 specimens were fixed with a locking plate. By use of an optical motion capture system, relative motion at the fracture site and failure load were evaluated during a cyclic loading protocol.

RESULTS

Plate osteosynthesis showed the highest cyclic load to failure (895 ± 239 N; range, 597-1135 N), followed by construct B (692 ± 121 N; range, 432-788 N) and construct A (350 ± 190 N; range, 139-615 N). Statistically significant differences were found between plating and construct A (P < .001), between plating and construct B (P = .031), and between construct B and construct A (P = .013). Relative motion at the fracture site, in terms of change in distance during cyclic loading, was lowest with construct B measured at the peak load of 395 N after 11 steps (1.73 ± 1.98 mm; range, 0.53-5.96 mm) and highest with construct A (8.46 ± 10.67 mm; range, 2.26-20.79 mm). Angular change measured at the peak load after 11 steps was lowest with construct B (1.19° ± 0.36°; range, 0.59°-1.7°) and highest with construct A (2.44° ± 1.63°; range, 0.77°-4.04°). Statistically significant differences were found between construct A and construct B and between construct A and plating at various steps of cyclic loading.

CONCLUSION

In this biomechanical study of unstable 3-part proximal humeral fractures, locking plate osteosynthesis demonstrated the highest possible load application. External fixator application with 8 threaded wires (construct B) revealed the least relative motion at the fracture site, without a statistically significant difference compared with locking plates. It therefore represents another valid technique for treatment regarding primary stability. The use of external fixator application with 6 threaded wires (construct A) resulted in the lowest stability and the highest rates of displacement.

Clinical and functional outcomes of a novel transosseous device to treat rotator cuff tears: A minimum 2-year follow-up

PURPOSE

Despite the improvements in the repair equipment techniques of rotator cuff, a gold standard method has not been defined yet and transosseous fixation through deltoid-splitting (mini-open) approach is still regarded as a good option. The primary purpose of this study is to present satisfactory clinical and functional outcomes with a novel transosseous device in full-thickness rotator cuff tear through deltoid-splitting.

MATERIALS AND METHODS

This retrospective study was performed on 70 consecutive patients who underwent surgery by a single surgeon from June 2014 to June 2016 for a full-thickness rotator cuff tear and was managed with a novel transosseous device. Total number of patients, mean age, percentage of male and female patients, mean duration of follow-up, percentage of involvement of the dominant extremity, affected shoulder, and tear size were recorded. Functional and clinical outcomes were assessed baseline and postoperatively at 3 and 6 months and final follow-up using Disabilities of the Arm, Shoulder and Hand (Q-DASH) and Constant-Murley scores.

RESULTS

A total of 70 (49 (70%) female, 21 (30%) male) patients whose mean age was 58.66 ± 9.19 (38-77) years were included. The mean surgery time was 35.33 ± 5.34 (28-55) min. The mean follow-up time was 28.31 ± 3.03 (24-36) months. According to the DeOrio and Cofield classification, 15 (21.43%) tears were small, 33 (47.14%) medium, 16 (22.86%) large, and 6 (8.57%) massive. By the final follow-up, the mean Constant-Murley score had significantly improved from 27.67 ± 7.46 (13-41) to 81.25 ± 3.77 (74-87; p = 0.0001) and the Q-DASH score had decreased from 82.34 ± 10.37 (65.91-100) to 10.28 ± 6.88 (0-23.45; p = 0.0001). There were no significant differences in the Constant-Murley or Q-DASH score at baseline-final follow-up between the small, medium, large, and massive tear groups (p > 0.05).

CONCLUSIONS

Treatment of full-thickness rotator cuff tear using this novel transosseous device significantly improved functional and clinical scores. However, further long-term prospective randomized multicenter trials involving comparative studies are necessary to confirm these findings.

Functional and Radiographic Outcomes After Arthroscopic Transosseous Suture Repair of Medium Sized Rotator Cuff Tears

PURPOSE

To evaluate the functional and anatomical outcomes after arthroscopic transosseous suture (TOS) repair of 2 to 4 cm sized rotator cuff tears and to identify preoperative factors influencing repair failure.

METHODS

From May 2013 to August 2014, patients with symptomatic 2 to 4 cm full-thickness tears underwent arthroscopic TOS repair, and those who could be followed up for a minimum of 2 years were included in this retrospective study. Functional and anatomical outcomes were analyzed up to 2 years postoperatively. Factors affecting cuff repair failure were evaluated, using both univariate and multivariate analyses.

RESULTS

Twenty-seven patients were included. On preoperative magnetic resonance imaging data, the mean anteroposterior dimension tear size was 27.0 ± 3.3 mm and mean retraction was 30.7 ± 3.1 mm. Anatomic failure (Sugaya III, IV, and V) rate was 33% with arthroscopic TOS repair; however, significant improvements were found regardless of cuff healing. Mean American Shoulder and Elbow Surgeons score (range, 0-100) improved from 48.8 ± 16.6 preoperatively to 80.1 ± 11.1 postoperatively (P < .001), mean Constant score (range, 0-100) improved from 54.5 ± 11.8 to 73.7 ± 8.5 (P < .001), and mean pain visual analog scale score (range, 0-10) improved from 3.9 ± 1.7 to 2.0 ± 1.1 (P < .001). These changes reached each minimal clinically important difference previously reported. Greater tear size in anteroposterior dimension (P = .034), decreased acromiohumeral distance (P = .022), and higher fatty infiltration of supraspinatus (P = .011) were independent preoperative factors associated with repair failure. Twelve patients (44%) experienced intraoperative bone laceration.

CONCLUSIONS

Arthroscopic TOS repair was a reliable technique for patients with 2 to 4 cm size rotator cuff tear. Preoperative factors associated with cuff repair failure were greater tear size in anteroposterior dimension, decreased acromiohumeral distance, and higher fatty infiltration of supraspinatus.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Arthroscopic transosseous rotator cuff repair: technical note, outcomes, and complications

The goal of this study was to review the authors' initial experience with arthroscopic transosseous rotator cuff repair. Thirty-one patients with full-thickness rotator cuff tears underwent arthroscopic transosseous rotator cuff repair over a 15-month period. Preoperatively, demographics and subjective scores were recorded. Postoperatively, pain levels, subjective shoulder values, satisfaction scores, American Shoulder and Elbow Surgeons (ASES) scores, complications, and reoperations were noted with a minimum 2-year follow-up. The relationships between pre- and intraoperative variables and outcome scores were determined with univariate analysis. Average patient age was 56 years, and 23 patients (74%) were men. Twenty patients (65%) underwent primary rotator cuff repair, and 11 patients (35%) underwent revision repair. Average time to follow-up was 26 months. Average preoperative pain level and subjective shoulder value were 5.1 of 10 and 35%, respectively. Average postoperative scores included pain level of 0.9 of 10, subjective shoulder value of 84%, satisfaction score of 90.6 of 100, and ASES score of 86.3 of 100. There were 3 (9.7%) major and 2 (6%) minor complications. Patients undergoing revision rotator cuff repair had significantly worse outcomes (pain level, subjective shoulder value, ASES score; P<.05) compared with those undergoing primary repair, and cortical augmentation did not significantly affect outcome. Overall, outcomes after arthroscopic transosseous rotator cuff repair are good, although patients undergoing revision repair do not have the same outcomes as those undergoing primary cuff repair. The procedure is not without complications (9.7% major, 6% minor complications). Cortical augmentation may be used to supplement fixation, although it does not necessarily affect outcomes. Patients without such augmentation may be at increased risk for suture cutout through the bone.

Surgical treatment of proximal humeral fracture with external fixator

BACKGROUND

The treatment of unstable displaced proximal humeral fractures remains challenging and controversial. Reports about the application of a mini-external fixator in the treatment of proximal humeral fractures are rare. The objective of this retrospective study was to evaluate the efficacy and complications of surgical treatment of proximal humeral fractures by closed reduction and external fixation with application of a mini-external fixator.

METHODS

Thirty-two patients with displaced proximal humeral fractures were surgically treated by closed reduction and external fixation with mini-external fixators at our institute between March 2007 and June 2009. There were 22 men and 10 women who had a mean age of 56 years (range, 23-81 years). The Neer scoring system related to pain, function, and range of motion was used to assess the outcome.

RESULTS

All the patients were followed up at an mean of 18 months (range, 13-27 months). The duration of surgery was 29 ± 12 minutes. The accumulative fluoroscopy time was 12 ± 3.5 exposures. The mean time of fracture union was 13 ± 3.6 weeks. The mean Neer score was 83.2 ± 12.5 points at final follow-up. The incidence of excellent and good results was 81%. Two patients had loosening of the pins. One patient had a collapsed humeral head. There was no infection and impingement.

CONCLUSION

The surgical treatment of displaced proximal humeral fractures with a mini-external fixator is characterized by minimal invasion, a shorter duration of surgery, and easy manipulation, making application of the mini-external fixator a good option for some selected patients.

Arthroscopic bone tunnel augmentation for rotator cuff repair

Transosseous repair of the rotator cuff has been shown to recreate the anatomic rotator cuff footprint in a secure and cost-efficient manner. However, the potential for sutures cutting through bone remains a concern with this strategy. Devices have been used successfully during open transosseous rotator cuff repair to augment the bone tunnels, potentially avoiding suture cut-out through the weak bone of the greater tuberosity. Recently, arthroscopic transosseous fixation of rotator cuff tears has become an alternative to arthroscopic suture anchor and open transosseous techniques. This method is expected to have the same potential pitfalls at the bone-suture interface as the open technique. The authors describe a technique for rotator cuff repair using a secure method of arthroscopic bone tunnel augmentation.

A quantitative method for determining medial migration of the humeral head after shoulder arthroplasty: preliminary results in assessing glenoid wear at a minimum of two years after hemiarthroplasty with concentric glenoid reaming

HYPOTHESIS

Glenoid erosion and medial migration of the humeral head prosthesis have been observed after most types of shoulder arthroplasty. A method of measuring the change in humeral head position with time after shoulder prosthetic arthroplasty was applied it to 14 shoulders that underwent humeral hemiarthroplasty with concentric glenoid reaming. We hypothesized that the measurement technique would be reproducible and that the rate of wear would be small in the series of shoulders studied.

MATERIALS AND METHODS

Standardized anteroposterior and axillary radiographs were obtained after surgery. Two examiners measured the position of the humeral head center in relation to scapular reference coordinates for the anteroposterior and axillary projections and plotted these values against time after surgery. The change in position was characterized as the slope of this plot. Shoulders were included if there were at least 3 sets of postoperative films, the last being at least 2 years after surgery.

RESULTS

The slopes measured by the 2 examiners agreed within 0.5 mm/y for the anteroposterior and the axillary projections. For the series of shoulder arthroplasties, the rate of movement of the head center toward the scapula was less than 0.4 mm/y for either examiner in either projection.

DISCUSSION

Medial migration is a concern after any type of shoulder arthroplasty, whether a hemiarthroplasty, a biological interpositional arthroplasty, or a total shoulder arthroplasty. Quantifying the rate of medial migration over time after shoulder arthroplasty is an important element of clinical follow-up.

CONCLUSIONS

This is an inexpensive, practical, and reproducible method that can be used to determine the rate of medial migration of the humeral head on plain radiographs after shoulder arthroplasty. The average rate of medial migration in the shoulders in this study was small.