Interobserver reliability of the rotator cable and its relationship to rotator cuff congruity

Transtendon Repair Under Switching-Scope Technique for Articular Partial-Thickness Rotator Cuff Tears

Partial-thickness rotator cuff tears are common diseases causing pain and disability. Among the different surgical methods, the transtendon repair technique is recommended due to its biomechanically superiority. However, this technique has a high learning curve and is time-consuming. In this Technical Note, we introduce a safer and more effective modified transtendon repair technique. Our switching-scope technique sets a switching stick into the glenohumeral joint through the posterior portal and is used as a guide for switching the arthroscope between the subacromial and articular spaces. This technique can reduce surgical time and overcome the disadvantage of vision limitation in articular-sided transtendon repair.

The Rotator Cable Does Not Stress Shield the Crescent Area During Shoulder Abduction

BACKGROUND

It is accepted by the orthopaedic community that the rotator cable (RCa) acts as a suspension bridge that stress shields the crescent area (CA). The goal of this study was to determine if the RCa does stress shield the CA during shoulder abduction.

METHODS

The principal strain magnitude and direction in the RCa and CA and shoulder abduction force were measured in 20 cadaveric specimens. Ten specimens underwent a release of the anterior cable insertion followed by a posterior release. In the other 10, a release of the posterior cable insertion was followed by an anterior release. Testing was performed for the native, single-release, and full-release conditions. The thicknesses of the RCa and CA were measured.

RESULTS

Neither the principal strain magnitude nor the strain direction in either the RCa or the CA changed with single or full RCa release (p ≥ 0.493). There were no changes in abduction force after single or full RCa release (p ≥ 0.180). The RCa and CA thicknesses did not differ from one another at any location (p ≥ 0.195).

CONCLUSIONS

The RCa does not act as a suspension bridge and does not stress shield the CA. The CA primarily transfers shoulder abduction force to the greater tuberosity.

CLINICAL RELEVANCE

The CA is important in force transmission during shoulder abduction, and efforts should be made to restore its continuity with a repair or reconstruction.

Characteristics and outcomes of L-shaped and reverse L-shaped rotator cuff tears

AIMS

The aim of this study was to compare the characteristics and outcomes of L-shaped and reverse L-shaped rotator cuff tears.

METHODS

A total of 82 shoulders (81 patients) after arthroscopic rotator cuff repair were retrospectively enrolled. The mean age of the patients was 62 years (SD 6), 33 shoulders (40.2%) were in male patients, and 57 shoulders (69.5%) were the right shoulder. Of these, 36 shoulders had an L-shaped tear (group L) and 46 had a reverse L-shaped tear (group RL). Both groups were compared regarding characteristics, pre- and postoperative pain, and functional outcomes. Muscle status was assessed by preoperative MRI, and re-tear rates by postoperative ultrasonography or MRI.

RESULTS

Patients in group RL were significantly older than in group L (p = 0.008), and group RL was significantly associated with female sex (odds ratio 2.5 (95% confidence interval 1.03 to 6.32); p = 0.041). Mean postoperative pain visual analogue scale (VAS) score was significantly greater (group L = 0.8 (SD 1.5), group RL = 1.7 (SD 2.2); p = 0.033) and mean postoperative American Shoulder and Elbow Surgeons (ASES) score was significantly lower in group RL than group L (group L = 91.4 (SD 13.1), group RL = 83.8 (SD 17.9); p = 0.028). However, postoperative mean VAS for pain and ASES score were not lower than the patient-acceptable symptom state scores. Mean retracted tear length was significantly larger in group L (group L = 24.6 mm (SD 6.5), group RL = 20.0 mm (SD 6.8); p = 0.003). Overall re-tear rate for 82 tears was 11.0% (nine shoulders), and re-tear rates in group L and RL were similar at 11.1% (four shoulders) and 10.9% (five shoulders), respectively (p = 1.000). No significant intergroup difference was found for fatty degeneration (FD) or muscle atrophy. Within group L, postoperative FD grades of supraspinatus and subscapularis worsened significantly (p = 0.034 and p = 0.008, respectively). Mean postoperative pain VAS (male = 1.2 (SD 1.8), female = 1.3 (SD 2.0)) and ASES scores (male = 88.7 (SD 15.5), female = 86.0 (SD 16.8)) were similar in male and female patients (p = 0.700 and p = 0.475, respectively). Regression analysis showed age was not a prognostic factor of postoperative pain VAS or ASES scores (p = 0.188 and p = 0.150, respectively).

CONCLUSION

Older age and female sex were associated with reverse L-shaped tears. Although the postoperative functional outcomes of patients with reverse L-shaped tears were satisfactory, the clinical scores were poorer than those of patients with L-shaped tears. Surgeons should be aware of the differences in clinical outcome between L-shaped and reverse L-shaped rotator cuff tears. Cite this article: Bone Joint J 2022;104-B(3):394-400.

Locating the rotator cable during subacromial arthroscopy: bursal- and articular-sided anatomy

BACKGROUND

The rotator cable (RCa) is an important articular-sided structure of the cuff capsular complex that helps prevent suture pull out during rotator cuff repairs (RCRs) and plays a role in force transmission. Yet, the RCa cannot be located during bursal-sided RCRs. The purpose of this study is to develop a method to locate the RCa in the subacromial space and compare its bursal- and articular-sided dimensions.

METHODS

In 20 fresh-frozen cadaveric specimens, the RCa was found from the articular side, outlined with stitches, and then evaluated from the bursal side using an easily identifiable reference point, the intersection of a line bisecting the supraspinatus (SS) tendon and posterior SS myotendinous junction (MTJ). Four bursal-sided lengths were measured on the SS-bisecting line as well as the RCa's outside anteroposterior base. For the articular-sided measurements, the rotator cuff capsular complex was detached from bone and optically scanned creating 3D solid models. Using the 3D models, 4 articular-sided lengths were made, including the RCa's inside and outside anteroposterior base.

RESULTS

The RCa's medial arch was located 9.9 ± 5.6 mm from the reference point in 10 intact specimens and 4.1 ± 2.4 mm in 10 torn specimens (P = .007). The RCa's width was 10.9 ± 2.1 mm, and the distance from the lateral edge of the RCa to the lateral SS insertion was 13.9 ± 4.8 mm. The bursal- and articular-sided outside anteroposterior base measured 48.1 ± 6.4 mm and 49.6 ± 6.5 mm, respectively (P = .268). The average inside anteroposterior base measurement was 37.3 ± 5.9 mm.

DISCUSSION

The medial arch of the RCa can be reliably located during subacromial arthroscopy using the reference point, analogous to the posterior SS MTJ. The RCa is located 10 mm in intact and 4 mm in torn tendons (P = .007) from the posterior SS MTJ. If the above 6-mm shift in location of the RCa is not taken into consideration during rotator cuff suture placement, it could negatively affect time zero repair strength. The inside anteroposterior base of the RCa measures on average 37 mm; therefore, rotator cuff tears measuring >37 mm are at risk of rupturing part or all of the RCa's 2 humeral attachments, which if not recognized and addressed could impact postoperative function.

Good outcome after repair of trauma-related anterosuperior rotator cuff tears-a prospective cohort study

BACKGROUND

Anterosuperior rotator cuff tears with a displaced long head of the biceps tendon are most often trauma-related, and patients with these conditions often present with severe pain and shoulder dysfunction. Repair of the subscapularis and supraspinatus and a biceps tenodesis or a tenotomy are the recommended treatments based on retrospective studies. The aim of this study was to prospectively evaluate clinical and structural treatment outcome in a cohort of trauma-related anterosuperior injuries in patients with previously healthy shoulders.

MATERIALS AND METHODS

Patients seeking care for a suspected rotator cuff injury after shoulder trauma were screened according to a protocol including clinical examination, baseline scoring with Western Ontario Rotator Cuff Index (WORC) and numeric rating scale of pain, ultrasound, and magnetic resonance imaging (MRI). Those with anterosuperior injuries were offered surgical treatment, structured postoperative physiotherapy, and inclusion in the present study with 1-year follow-up, including MRI, baseline scores, Constant-Murley score, and Patient Global Impression of Change. Thirty-three patients (78% men) with a mean age of 59 (40-76) years were included.

RESULTS

All patients had a biceps pulley lesion, a displaced biceps tendon, and incomplete full-thickness subscapularis and supraspinatus tears. Six patients declined surgery. At follow-up, the operated patients reached a median WORC score of 86% and a median change from baseline to follow-up of 50% (P = .0001). Pain decreased (P = .0001) at rest, at night, and during activity. The median Constant-Murley score was 86% of the contralateral nonoperated shoulder, 58% of the contralateral abduction strength recovered after surgery, and 86% reported that they were recovered or much improved. All repairs and tenodeses healed except for 2 supraspinatus tendons. The 6 nonoperated patients reached a median WORC score of 90, a change in the median value from baseline to follow-up of 31, but reported more pain, and a smaller proportion considered themselves as recovered or much improved. In all patients, the 1-year MRIs had signal changes in the upper muscular portion of subscapularis, consistent with fatty infiltration, regardless of operative or nonoperative treatment.

CONCLUSION

Anterosuperior rotator cuff injury with an associated pulley lesion and displaced long head of the biceps tendon may be treated successfully with surgery as the majority of patients in our cohort clinically recovered or were much improved without pain after a year. With a 1-year perspective, nonoperatively treated patients may also reach a reasonable clinical outcome. Independently of treatment or tendon healing, residual subscapularis muscle injury was seen, which may have long-term implications.

Anterior Cable Tears in Arthroscopic Rotator Cuff Repairs

Purpose

To determine whether anterior cable tears could be identified at the time of arthroscopic rotator cuff repair and determine the characteristics of the anterior cable tears identified.

Methods

From 2016 to 2017 all shoulder arthroscopies had data collected prospectively at the time of surgery, specifically including injury to the capsular and tendon zones of insertion on the greater tuberosity. Anterior cable position and degree of injury and medialization were recorded, as well as complete findings of the diagnostic arthroscopy. The inclusion criterion was primary shoulder arthroscopy. The exclusion criterion was any revision shoulder arthroscopy. All arthroscopic rotator cuff repairs (ARCR) were grouped together and all other nonarthroscopic rotator cuff repair surgeries (non-ARCR) were grouped together.

Results

In total, 118 shoulder arthroscopies had data collected prospectively at the time of surgery: 90 primary shoulder arthroscopies met the inclusion criteria; 28 were excluded because they were revision surgeries. There were 42 patients in the ARCR group (Group 1). Six of these were partial tears, and 36 were full-thickness tears. There were 48 patients in the non-ARCR group (Group 2). The non-ARCR Group 2 served as an anatomic baseline for ARCR Group 1. In all 90 shoulders, the rotator cable and anterior cable were identified. Group 1 (ARCR) incidence of anterior cable tears with abnormal position was 71.4% compared to 2.1% in group 2 (non-ARCR) (P < .001) Group 1 (ARCR) incidence of anterior cable tears with normal anterior cable position (n = 12) was compared to abnormal anterior cable position (n = 30). Injury to the anterior footprint capsular and tendon zones were compared. Normal anterior cable position correlated with no or low-grade injury to anterior footprint capsular zone. (Nimura zone C1). Abnormal anterior cable displacement graded as moderate (n = 20) and severe (n = 10) were compared for injury to the anterior footprint. Moderate displacement correlated with complete or high grade injury to C1 in 85% and complete injury to R1 in 45% (P < .001 and .049). In severe displacement complete C1 injury was 100%, and complete R1 injury was 100% (P < .001 and .001).

Conclusions

Anterior cable tears are universally identified in ARCR. Three patterns of medial displacement severity correlated with injury to a crucial insertion zone (C1) at the anterior footprint. The degree of anterior cable disruption at the anterior footprint and displacement was commonly disproportionately greater than the injury to the supraspinatus.

Level of Evidence

Level III, diagnostic study.