Patterns of strain and the determination of the safe arc of motion after subscapularis repair—A biomechanical study

Knesek, Michael; Brunfeldt, Alexander; Korenczuk, Christopher; Jepsen, Karl J.; Robbins, Christopher; Gagnier, Joel; Allen, Answorth A.; Dines, Joshua S.; Bedi, Asheesh

doi:10.1002/jor.23045

Cited by 6 publications

(2 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The rotational orientation of the cylinder was adjusted under a low preload (< 5 N) to achieve linear alignment of the subscapularis tendon to the direction of pull. This was performed according to descriptions from previous studies [21,28,33] to simulate a hanging arm position (0°of abduction) and neutral humeral rotation (0°o f rotation). The bicipital groove was used as a reference to adjust humeral rotation.…”

Section: Biomechanical Testingmentioning

confidence: 99%

“…One aspect that can already predict a potential healing process in a biomechanical study is determining coverage of the footprint by the subscapularis tendon [21]. When the contact pressure between the tendon and the bone is higher, better biological healing can be expected [7,8,17,33]. Dyrna et al [21] used radiographs to measure contact pressure between the subscapularis tendon and the bony footprint.…”

Section: Limitationsmentioning

confidence: 99%

See 1 more Smart Citation

Are Knotted or Knotless Techniques Better for Reconstruction of Full-Thickness Tears of the Superior Portion of the Subscapularis Tendon? A Study in Cadavers

Sgroi

Kappe

Ludwig

et al. 2021

Clin Orthop Relat Res

View full text Add to dashboard Cite

BackgroundKnotted and knotless single-anchor reconstruction techniques are frequently performed to reconstruct full-thickness tears of the upper portion of subscapularis tendon. However, it is unclear whether one technique is superior to the other.Questions/purposes(1) When comparing knotless and knotted single-anchor reconstruction techniques in full-thickness tears of the upper subscapularis tendon, is there a difference in stiffness under cyclic load? (2) Are there differences in cyclic gapping between knotless and knotted reconstructions? (3) Are there differences in the maximal stiffness, yield load, and ultimate load to failure? (4) What are the modes of failure of knotless and knotted reconstruction techniques?MethodsEight matched pairs of human cadaveric shoulders were dissected, and a full-thickness tear of the subscapularis tendon (Grade 3 according to the Fox and Romeo classification) was created. The cadavers all were male specimens, with a median (range) age of 69 years (61 to 75). Before biomechanical evaluation, the specimens were randomized into two equal reconstruction groups: knotless single anchor and knotted single anchor. All surgical procedures were performed by a single orthopaedic surgeon who subspecializes in sports orthopedics and shoulder surgery. With a customized set up that was integrated in a dynamic material testing machine, the humeri were consecutively loaded from 10 N to 60 N, from 10 N to 100 N, and from 10 N to 180 N for 50 cycles. Furthermore, the gapping behavior of the tear was analyzed using a video tracking system. Finally, the stiffness, gapping, maximal stiffness, yield loads, and maximum failure loads of both reconstruction groups were statistically analyzed. Failure was defined as retearing of the reconstructed gap threshold due to rupture of the tendon and/or failure of the knots or anchors. After biomechanical testing, bone quality was measured at the footprint of the subscapularis using microCT in all specimens. Bone quality was equal between both groups. To detect a minimum 0.15-mm difference in gap formation between the two repair techniques (with a 5% level of significance; α = 0.05), eight matched pairs (n = 16 in total) were calculated as necessary to achieve a power of at least 90%.ResultsThe first study question can be answered as follows: for stiffness under cyclic load, there were no differences with the numbers available between the knotted and knotless groups at load stages of 10 N to 60 N (32.7 ± 3.5 N/mm versus 34.2 ± 5.6 N/mm, mean difference 1.5 N/mm [95% CI -6.43 to 3.33]; p = 0.55), 10 N to 100 N (45.0 ± 4.8 N/mm versus 45.2 ± 6.0 N/mm, mean difference 0.2 N/mm [95% CI -5.74 to 6.04]; p = 0.95), and 10 N to 180 N (58.2 ± 10.6 N/mm versus 55.2 ± 4.7 N/mm, mean difference 3 N/mm [95% CI -5.84 to 11.79]; p = 0.48). In relation to the second research question, the following results emerged: For cyclic gapping, there were no differences between the knotted and knotless groups at any load levels. The present study was able to show the following wi...

show abstract

Section: Biomechanical Testingmentioning

confidence: 99%

Section: Limitationsmentioning

confidence: 99%

Are Knotted or Knotless Techniques Better for Reconstruction of Full-Thickness Tears of the Superior Portion of the Subscapularis Tendon? A Study in Cadavers

Sgroi

Kappe

Ludwig

et al. 2021

Clin Orthop Relat Res

View full text Add to dashboard Cite

show abstract

Maximum in-vivo joint contact forces double during active compared to assisted motion in the glenohumeral joint and decline long-term due to rotator cuff pathologies

Harti,

Schrednitzki,

Damm

et al. 2024

Arch Orthop Trauma Surg

View full text Add to dashboard Cite

Rotator cuff repair: post-operative rehabilitation concepts

Sgroi

Cilenti

2018

Curr Rev Musculoskelet Med

View full text Add to dashboard Cite

Purpose of review With improvements in surgical techniques and increased knowledge of rotator cuff healing, there was a need to identify a safe progression after rotator cuff repair. The rehabilitation specialist plays an integral role in the care of these patients, and by implementing an evidence and criteria-based model, patients may be able to return to their prior levels of function sooner with fewer complications. Recent findings Timing of progression for rotator cuff patients should align not only with healing but also potential strain on the involved tissue. Recent electromyography studies have identified exercises which elicit highest level of muscle activation for individual dynamic stabilizers. The physical therapist should also be aware of potential complications and be prepared to manage appropriately if they should arise. Summary During rehabilitation after rotator cuff repair, there should be constant communication with the surgical team. Awareness of complication management, healing potential of the repaired tendon, and anatomy of the shoulder complex are critical. During the early stages, reducing pain and inflammation should be prioritized followed by progressive restoration of range of motion. When advancing range of motion, progression from passive, active assisted, and active movements allow for gradual introduction of stress to the healing construct. Even though time frames are not used for progression, it is important not to place excessive stress on the shoulder for up to 12 weeks to allow for proper tendonto-bone healing. As exercises are progressed, scapular muscle activation is initiated, followed by isometric and lastly isotonic rotator cuff exercises. When treating overhead athletes, advanced strengthening in the overhead position is performed, followed by plyometric training. Advanced strengthening is initiated when all preceding criteria have been met. It is important that patients are educated early in the rehabilitation process so that they can manage their expectations to realistic time frames.

show abstract

Patterns of strain and the determination of the safe arc of motion after subscapularis repair—A biomechanical study

Cited by 6 publications

References 36 publications

Are Knotted or Knotless Techniques Better for Reconstruction of Full-Thickness Tears of the Superior Portion of the Subscapularis Tendon? A Study in Cadavers

Are Knotted or Knotless Techniques Better for Reconstruction of Full-Thickness Tears of the Superior Portion of the Subscapularis Tendon? A Study in Cadavers

Maximum in-vivo joint contact forces double during active compared to assisted motion in the glenohumeral joint and decline long-term due to rotator cuff pathologies

Rotator cuff repair: post-operative rehabilitation concepts

Contact Info

Product

Resources

About