Outcome after failed traumatic anterior shoulder instability repair with and without surgical revision.

The purpose of this study was to evaluate the incidence and reasons of recurrent instability in patients with traumatic anterior shoulder instability and to document the clinical results with regard to the number of stabilizing procedures. Twenty-four patients with failed primary open or arthroscopic anterior shoulder stabilization were followed for a mean of 68 (36-114) months. Following recurrence of shoulder instability, eight patients chose not to be operated on again, whereas 16 underwent repeat stabilization. A persistent or recurrent Bankart lesion was found in all 16 patients and concomitant capsular redundancy in 4. After the first revision surgery, further instability occurred in 8 patients, and 6 of them were stabilized a third time. Only 7 patients (29%) achieved a good or excellent result according to the Rowe score. All shoulder scores improved after revision stabilization. However, the number of stabilizing procedures adversely affected the outcome scores, as well as postoperative range of motion and patient satisfaction. Recurrent instability after a primary stabilization procedure represents a difficult diagnostic and surgical challenge, and careful attention should be paid to address persistent or recurrent Bankart lesions and concomitant capsular reduncancy. A satisfying functional outcome can be expected mainly in patients with one revision surgery. Further stabilization attempts are associated with poorer objective and subjective results.

Arthroscopic Bankart repair in traumatic anterior shoulder instability using a suture anchor technique.

PURPOSE: The purpose of this study was to prospectively evaluate the surgical outcome of arthroscopic Bankart repair via suture anchors in patients with recurrent traumatic anterior shoulder instability with a minimum follow-up of 2 years. METHODS: We included 54 consecutive patients without an osseous Bankart lesion of greater than 25% of the glenoid circumference with a mean age of 25.3 years (range, 16 to 58 years) undergoing arthroscopic Bankart repair via suture anchors for traumatic anterior shoulder instability. The mean follow-up was 3.7 years (range, 2.3 to 5.2 years) at the final follow-up examination. Patients were evaluated prospectively according to the rating scales of Rowe, the American Shoulder and Elbow Surgeons, and Constant and Murley. One patient was lost to follow-up. RESULTS: After 3.7 years, 4 patients had recurrent instability: 3 had redislocated and 1 had recurrent subluxations. Thus the overall redislocation rate was 7.5%. Of the 4 redislocators, 3 had a traumatic onset of the redislocation. All shoulder scores (Rowe, American Shoulder and Elbow Surgeons, and Constant and Murley) revealed highly significant improvements postoperatively. At final follow-up, 85.7% of patients had returned to their preoperative sports level. CONCLUSIONS: Our results in this series demonstrate the efficacy of arthroscopic Bankart repair with suture anchors for the treatment of recurrent traumatic anterior shoulder instability with respect to recurrence rate, range of motion, and shoulder function during a mean follow-up of 3.7 years. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Long-term results of arthroscopic Bankart repair with a bioabsorbable tack.

BACKGROUND: Short-term to midterm data are available on arthroscopic shoulder stabilization using bioabsorbable tacks or suture anchors. It remains unknown whether these techniques can equal the success of open Bankart repair in the long term. PURPOSE: To assess the long-term outcome of arthroscopic Bankart repair using bioabsorbable tacks in patients with traumatic anterior shoulder instability with a minimum follow-up of 7 years. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Treatment outcomes were determined prospectively according to the Rowe score and retrospectively according to the Constant and American Shoulder and Elbow Surgeons scores. Included in this study were 18 consecutive patients with a mean age of 26.8 years (range, 16-62 years) who underwent arthroscopic Bankart repair using bioabsorbable tacks for traumatic anterior shoulder instability. The study group consisted of 14 male and 4 female patients. The mean follow-up was 8.7 years (range, 7.0-9.8 years). RESULTS: One patient had recurrent dislocations requiring further surgery, for an overall failure rate of 5.6%. An additional patient had 1 traumatic subluxation episode within the first postoperative year that did not recur. According to the Rowe score, which increased to 90.3 (17.8) from 32.8 (8.3) points preoperatively, 15 patients (83.3%) achieved a good or excellent result. The mean Constant score was 91.3 (SD, 6.9) points, and the mean American Shoulder and Elbow Surgeons score was 92.1 (SD, 6.9) points postoperatively. A return to the preinjury level of sports competition was reported by 64% of patients. No signs of synovitis occurred in any patient postoperatively. CONCLUSION: Arthroscopic Bankart repair for the treatment of recurrent traumatic anterior shoulder instability repair using bioabsorbable tacks offers reliable results with respect to failure rate, range of motion, and shoulder function during a minimum follow-up of 7.0 years. In contrast to previous reports on arthroscopic Bankart repair, results did not deteriorate during follow-up.

The influence of arthroscopic subscapularis tendon and anterior capsular release on glenohumeral translation: a biomechanical model.

The effect of an arthroscopic release of the intraarticular portion of the subscapularis tendon and the anterior capsule on glenohumeral translation was investigated in a cadaveric model. Ten human cadaveric shoulders with a mean age of 63.5 years (range, 52-79 years) were tested in a robot-assisted shoulder simulator. Joint translation was measured before and after an arthroscopic release of the intraarticular portion of the subscapularis tendon and a subsequent release of the anterior capsule at 0 degrees , 30 degrees , 60 degrees , and 90 degrees of glenohumeral elevation. Translation was measured in the anterior, anterior-inferior, and inferior directions under 20 N of applied load. Testing of the specimen revealed that the release of the intraarticular portion of the subscapularis tendon and the anterior capsule increased translation in all directions. Significant increases in translation were observed after release of the intraarticular portion of the subscapularis tendon in the midrange of motion. The influence of the arthroscopic capsular release, in conjunction with the release of the subscapularis tendon, was very high above 60 degrees of elevation. The study indicates that the intraarticular component of the subscapularis tendon functions as a restraint to anterior-inferior translation primarily in the midrange of glenohumeral motion, whereas the anterior capsule adds anterior-inferior stability to the glenohumeral joint mainly above 60 degrees of elevation.

Quantitative assessment of glenohumeral translation after anterior shoulder dislocation and subsequent arthroscopic bankart repair.

BACKGROUND: During the past decade, developments in arthroscopic technology have made arthroscopic repair of labral lesions feasible. However, results with the use of the transglenoid suture technique, or with the use of bioabsorbable tacks, have remained variable in the literature, and the recurrence rates are still inferior to those of open Bankart repair. HYPOTHESIS: Arthroscopic Bankart repair with suture anchors can re-create translational and rotational range of motion of the intact glenohumeral joint, and the number of preoperative dislocations has an influence on the result. STUDY DESIGN: Controlled laboratory study. MATERIALS: Twelve cadaveric shoulders were tested in a robot-assisted shoulder simulator. Anterior and posterior translation and external rotation were measured for intact, dislocated (shoulders were randomly selected to 1 of 3 groups, which were dislocated 1, 3, or 7 times), and repaired conditions at 0 degrees and 90 degrees of glenohumeral elevation. RESULTS: After shoulder dislocation, a significant increase was found in translation and rotation, confirming the creation of a traumatic shoulder instability model. Further testing of the specimen revealed that translational and rotational ranges of motion were reduced by arthroscopic Bankart repair at both testing positions. External rotation was decreased significantly at 0 degrees and 90 degrees of abduction. No significant differences were found between the 3 dislocation groups. CONCLUSION: The results demonstrate a sufficient biomechanical performance of arthroscopic Bankart repair using suture anchors in a traumatic anterior shoulder instability model. With the numbers available, no relationship was found between the number of dislocations and the postoperative result concerning translational or rotational motion. CLINICAL RELEVANCE: Glenohumeral translation and rotation after arthroscopic Bankart repair with use of suture anchors approached near normal values, confirming the clinical success of this technique.

Cellularity and apoptosis after radiofrequency-induced shrinkage of collagenous tissue: assessment of postoperative immobilization using an in vivo rabbit model.

BACKGROUND: Electrothermally-assisted capsular shrinkage has been gaining increased acceptance in the treatment of shoulder instability. Its indication in ACL-deficient knees has been discussed recently. METHODS: We examined the influence of immobilization on cell homeostasis of healing collagenous tissue after radiofrequency energy was applied to the patellar tendon in 23 rabbits. The animals were killed immediately after surgery (n = 6) or 3 weeks after surgery (n = 17). 10 rabbits were allowed normal cage activity, whereas the treated hind limb of 7 animals was immobilized for 3 weeks in a cast. Feulgen staining was used to stain the DNA of cell nuclei. Cells undergoing apoptosis were identified by the TUNEL method. Quantitative histological assessment was performed using imaging analysis software. RESULTS: Severe cellular damage in RF-treated collagenous tissue was partly induced by the immediate onset of apoptosis. At 3 weeks after surgery, non-immobilized tendon showed increased cellularity and apoptosis, whereas immobilization prevented the increase in cellularity and apoptosis significantly. The calculated ratio of apoptosis was not influenced by any postoperative treatment. INTERPRETATION: Diminished cellularity and apoptosis during tissue remodeling, due to immobilization, may protect the shortened collagenous scaffold from stretching and further optimize the clinical outcome after radiofrequency shrinkage. To stabilize the shrunken tissue, proliferation during postoperative wound healing should be minimized by careful rehabilitation.

A modified capsular shift for atraumatic anterior-inferior shoulder instability.

PURPOSE: To evaluate the long-term outcome of a modified inferior capsular shift procedure in patients with atraumatic anterior-inferior shoulder instability by analyzing a consecutive series of patients who had undergone a modified inferior capsular shift for this specific type of shoulder instability. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1992 and 1997, 38 shoulders of 35 patients with atraumatic anterior-inferior shoulder instability that were unresponsive to nonoperative management were operated on using a modified capsular shift procedure with longitudinal incision of the capsule medially and a bony fixation of the inferior flap to the glenoid and labrum in the 1 o'clock to 3 o'clock position. The patient study group consisted of 9 men and 26 women with a mean age of 25.4 years (range, 15-55 years) at the time of surgery. The mean follow-up was 7.4 years (range, 4.0-11.4 years); 1 patient was lost to follow-up directly after surgery. The study group was evaluated according to the Rowe score. RESULTS: After 7.4 years, 2 patients experienced a single redislocation or resubluxation, 1 patient had recurrent dislocations, and 1 patient had a positive apprehension sign, which is an overall redislocation rate of 10.5%. The average Rowe score increased to 90.6 (SD = 19.7) points from 36.2 (SD = 13.5) points before surgery. Seventy-two percent of the patients participating in sports returned to their preoperative level of competition. CONCLUSIONS: Results in this series demonstrate the efficacy and durability of a modified capsular shift procedure for the treatment of atraumatic anterior-inferior shoulder instability.

Does immobilization after radiofrequency-induced shrinkage influence the biomechanical properties of collagenous tissue? An in vivo rabbit study.

BACKGROUND: Despite widespread use of radiofrequency-induced shrinkage of collagenous tissue, there have been no animal studies on the effects of postoperative immobilization on the biomechanical behavior of shrunken tissue. PURPOSE: To examine the role of postoperative immobilization after radiofrequency-induced shrinkage, with special emphasis on the biomechanical properties of shrunken collagenous tissue. STUDY DESIGN: Controlled laboratory study. METHODS: One patellar tendon of 66 New Zealand White rabbits was shrunk. Six rabbits were sacrificed immediately after surgery. Twenty rabbits were not immobilized, twenty were immobilized for 3 weeks, and twenty were immobilized for 6 weeks. The biomechanical parameters failure strength, stiffness, and relaxation were tested. RESULTS: Nine weeks after surgery, biomechanical parameters were still low compared to control tendons. Shrunken tendons did not reach levels of normal tissue at any time after surgery, regardless of whether the animals had been immobilized. According to time-related development, all biomechanical parameters had the lowest levels 3 weeks after surgery. Immobilized tendons demonstrated a better and faster recovery than nonimmobilized tendons compared to the immediate postoperative level. CONCLUSION: Postoperative immobilization supports recovery of biomechanical properties after shrinkage. Despite immobilization, biomechanical properties of shrunken tissue did not completely reach levels of normal tissue. CLINICAL RELEVANCE: Careful rehabilitation is imperative after radiofrequency-induced shrinkage. This animal model supports an immobilization period of at least 6 weeks after surgery.

Proprioception of the shoulder joint after surgical repair for Instability: a long-term follow-up study.

BACKGROUND: Proprioceptive capabilities play an important role in stability of the shoulder joint. HYPOTHESIS: Decreased proprioceptive capabilities can improve by surgical repair of shoulder instability. STUDY DESIGN: Prospective long-term study. METHODS: The proprioceptive capabilities of 14 patients with recurrent anterior shoulder instability were examined preoperative and with a minimum follow-up of 5 years postoperative using the angle reproduction test. The patients' data were compared to a healthy control group. RESULTS: The joint position sense improved significantly in abduction, flexion, and rotation (P <.05). The preoperative difference from the target joint position was 9.3 degrees (SD, 4.6 degrees ) for the summarized positions in abduction, 9.1 degrees (SD, 4.5 degrees ) in flexion, and 10.1 degrees (SD, 5.1 degrees ) in rotation. Postoperatively, it improved to 5.6 degrees (SD, 2.9 degrees ) in abduction, 5.6 degrees (SD, 2.7 degrees ) in flexion, and 5.0 degrees (SD, 1.8 degrees ) in rotation. The joint position sense of the uninvolved contralateral shoulder improved too. CONCLUSIONS: Five years after surgical repair for shoulder instability, the joint position sense improved significantly, to a level of normal, healthy shoulders.

Rasterstereographic back shape analysis in idiopathic scoliosis after posterior correction and fusion.

OBJECTIVE: To determine the accuracy of rasterstereographic three-dimensional back surface analysis and reconstruction of the spine in idiopathic scoliosis treated by posterior correction and fusion. DESIGN: Prospective imaging study of 25 patients with idiopathic scoliosis who underwent posterior correction and fusion and were followed for one year. BACKGROUND: In an earlier study published in this journal rasterstereography has proved to be an accurate imaging modality for quantifying the changes in the three-dimensional shape of the spine and posterior rib cage after anterior correction and fusion. Goal of the present study was to determine the accuracy for the more common posterior correction and fusion with attention paid to the presence of the posterior implants and scarring. METHODS: Twenty-five patients with idiopathic scoliosis with maximum Cobb angles of 78 degrees were examined by rasterstereography and radiography. Seventy-one anterior-posterior radiographs were digitised. Twenty-four were preoperative and 47 postoperative radiographs. Rasterstereographic and radiographic curves were compared by best-fit superimposition. Root-mean-square differences were calculated as parameters of accuracy. RESULTS: The accuracy of rasterstereography in severe idiopathic scoliosis with Cobb angles between 48 degrees and 78 degrees was satisfactory with root-mean-square differences of 5.8 mm for the lateral deviation and 4.8 degrees for vertebral rotation. Following posterior correction the accuracy was good. The root-mean-square difference was 4.5 mm for the lateral deviation and 4.3 degrees for vertebral rotation. CONCLUSION: The accuracy obtained for posteriorly-operated scolioses between 50 degrees and 80 degrees was similar to the findings for scolioses operated via anterior approach, as well as those with curves up to 50 degrees Cobb angle. Therefore rasterstereography can be used postoperatively to reduce the number of radiographs and radiation exposure. Additionally, the method provides an objective quantification of the postoperative improvement in the cosmesis of the back shape. RELEVANCE: In the treatment of severe idiopathic scoliosis rasterstereography provides both a considerable reduction of X-rays and an objective documentation of the cosmesis before after scoliosis surgery.

Results of suture anchor repair of anteroinferior shoulder instability: a prospective clinical study of 85 shoulders.

The results of an open Bankart procedure with use of suture anchors were evaluated in 85 shoulders in 83 patients. The mean age was 30 years (range, 16-59 years). The mean number of preoperative dislocations was 18.5. Patients were evaluated prospectively by the Rowe score. Eighty-five shoulders were followed for 1 year and seventy-seven for at least 2 years. The mean follow-up was 3.5 years (range, 1-8.3 years). The Rowe score increased from 30 to 92 points. An excellent or good result was found in 81 of 85 shoulders after 1 year and in 68 of 77 shoulders after 2 years. Seven redislocations occurred, four due to a new trauma. Two patients had recurrent subluxations, one due to a new trauma.

Neurohistological examination of the inferior glenohumeral ligament of the shoulder.

The neural histology of the anterior band of the inferior glenohumeral ligament (IGHL) was studied in 11 fresh shoulder specimen using a special silver impregnation technique. Between the collagen fibers small myelinated and unmyelinated dendrites could be detected. The appearance of neurovascular structures in the adjacent synovial layer clearly exceeded the typical supply to soft tissues. Analysing about 11,000 sections Ruffini mechanoreceptors that are known to be slow adapting were found on the humeral insertion of the band. The sections containing these neural end organs were identified by means of transillumination and reflection-contrast microscopy and reconstructed using three-dimensional image processing. The presence of neural structures including Ruffini corpuscles in these most important passive stabilizers of the shoulder joint shows that these ligaments function also as an active safety device. There slow adaption is a prerequisite for muscular reflexes counteracting the tensile stresses to which the passive stabilizing structures of the shoulder are exposed. A disruption of the continuity of these structures by mechanical forces or surgery can reduce the biofeedback and proprioceptive quality and thus lead to a decrease of shoulder function and/or stability. These observations should be taken into account when planning surgical interventions involving the IGHL. Procedures like capsule shifts or plications may affect mechanoreceptor orientation and concentrations, thereby affecting the interaction between these structures and the synergistic muscles. When possible, these intervention should avoid receptor-dense regions while attempting to restore normal anatomical orientation and tissue tension.

Influence of postoperative immobilization on tendon length after radiofrequency-induced shrinkage. An in vivo rabbit study.

BACKGROUND: Despite the widespread use of radiofrequency-induced shrinkage of collagenous tissues, there have been no animal studies on the effects of postoperative immobilization after such treatment. PURPOSE: To examine the effects of postoperative immobilization after radiofrequency energy treatment, with special emphasis on any tissue length increases. STUDY DESIGN: Controlled laboratory study. METHODS: The right patellar tendon of 60 New Zealand White rabbits was shrunk with a radiofrequency probe. Tendon length was measured intraoperatively before and after shrinkage and via radiographs immediately postoperatively and at 3, 6, and 9 weeks. Twenty rabbits were not immobilized, 20 were immobilized for 3 weeks, and 20 were immobilized for 6 weeks. RESULTS: In the nonimmobilized limbs, the tendon length increased 34.9% at 3 weeks and another 2.5% at 6 weeks, versus 11.2% at 3 weeks and 6.6% at 6 weeks in the immobilized limbs. Ten of the 20 rabbits that were immobilized for 6 weeks were sacrificed at 9 weeks and were found to have a further length increase of 10.8%. At 9 weeks, the tendons of this group were no longer significantly shorter than the tendons from rabbits that had not been immobilized. CONCLUSIONS: Careful postoperative rehabilitation is imperative after radiofrequency-induced shrinkage. Without protection, exposure to normal physiologic loads places the shrunken tissue at risk of stretching out beyond the preshrinkage length. CLINICAL RELEVANCE: Shrunken tissue is at risk of stretching out after radiofrequency-induced shrinkage.

Rasterstereographic back shape analysis in idiopathic scoliosis after anterior correction and fusion.

OBJECTIVE: To determine the accuracy of rasterstereographic three-dimensional back surface analysis and reconstruction of the spine in cases of severe idiopathic scoliosis treated by anterior correction and fusion. DESIGN: Comparison of digitized radiographic curves and rasterstereographic curves by best fit superimposition and calculation of root mean square differences as parameters of similarity. BACKGROUND: Rasterstereography has been proven to be accurate in scoliosis up to 50 degrees Cobb angle. Since 1989 the device is in clinical routine use for non-operatively treated patients and reduces the need for otherwise indispensable radiographs significantly. METHODS: Fifty two patients with severe idiopathic scoliosis with Cobb angles up to 88 degrees were examined rasterstereographically and radiographically. Forty eight pre-operative anterior-posterior radiographs and 101 post-operative anterior-posterior radiographs were digitized. Radiographic and rasterstereographic curves were compared and the root mean square differences were calculated as parameters of precision of rasterstereographic reconstruction. RESULTS: Accuracy of rasterstereography in idiopathic scoliosis with Cobb angles between 50 degrees and 88 degrees is satisfactory. The root mean square difference of the radiographic and rasterstereographic curves was 6.4 mm for lateral deviation and 4.5 degrees for vertebral rotation. After anterior scoliosis surgery the precision of the device is good. The root mean square difference for lateral deviation was 3.4 mm and 3.2 degrees for rotation. Considering both groups an average root mean square of 4.7 mm and 3.7 degrees was calculated. CONCLUSIONS: Accuracy in severe scoliosis up to 88 degrees Cobb angle was satisfactory. The results of this first evaluation of surgically treated severe scoliosis showed a good accuracy after anterior surgery. The system can be used for post-operative follow up examinations and may reduce the number of X-rays considerably. In contrast to radiography, CT or MRI rasterstereography provides an objective quantification and documentation of the post-operative cosmetic improvement of the back shape in standing posture. RELEVANCE STATEMENT: Based on the findings of this study rasterstereography in future enables both objective quantification of cosmetic improvement and significant reduction of X-rays in idiopathic scoliosis with Cobb angles higher than 50 degrees before and after anterior surgical correction and fusion.