Influence of T-shift capsulorrhaphy on rotation and translation of the glenohumeral joint: An experimental study

To evaluate changes in the response of capsuloligamentous restraints to translatory forces and rotation torques caused by experimental capsulorrhaphy (T-shift modification of Bankart repair), eight cadaveric shoulders were tested. Measurements were taken in intact and vented specimens, after severance of the anterior capsule at the glenoid rim (creating an artificial Bankart lesion), T-shaped incision of the anterior capsule, and refixation of the capsule (with a standard Bankart procedure) combined with tightening by T-shift. Rotation torques and translatory forces were applied in different positions of abduction with a specifically designed mounting apparatus that had four degrees of freedom. Dynamic and static measurements were performed with a tracking sysem that had six degrees of freedom. T-shift capsulorrhaphy restored the resistance of the capsuloligamentous restraints to translatory forces in all directions. This restoration was confirmed when we compared these results with data obtained from intact joints. No significant alteration of the centering mechanism resulting from rotation torques was observed, although the extent of external and internal rotation was remarkably decreased. This T-shift modification seems to produce a symmetric reduction of the volume of the capsule without significant displacement of the humeral head.     

Posterior capsulorrhaphy for treatment of recurrent posterior glenohumeral instability

The surgical treatment of recurrent posterior shoulder instability via a posterior approach has had a variable degree of success reported in the literature with recurrence rates ranging between 8% and 45%. The purpose of this study was to review the results of posterior capsulorrhaphy in a consecutive series of patients with recurrent posterior instability. Seventeen consecutive patients underwent operative management for posterior glenohumeral instability. The dominant shoulder was involved in ten patients. All patients were male with an average age of 28.1 years (range: 16 to 54 years). Ten patients had sustained a specific injury which precipitated the instability. Six patients reported dislocations requiring formal closed reduction maneuvers; the remainder described episodes of recurrent subluxation with spontaneous reduction. All patients underwent a posterior capsulorrhaphy using an infraspinatus splitting approach. Eight shoulders required repair of a posterior capsulolabral detachment. In addition, one patient required augmentation with a posterior bone block for significant glenoid rim deficiency. Outcome was assessed by personal interview, clinical assessment, and standardized radiographs. At an average follow-up of 3.9 years (range: 1.8 to 10.8 years) patients estimated their overall shoulder function to be 81% of the contralateral unaffected shoulder. The subjective result was excellent for eight patients, good for five patients, fair in two patients, and poor in two patients. One of the poor outcomes was in a patient with glenohumeral degenerative changes at the index procedure which progressed and eventually required a total shoulder arthroplasty. The other poor result was in a patient found to have a full-thickness rotator cuff tear 10.6 years after the index procedure. Two patients (12%) had recurrence of their instability. Both of these patients sustained a significant re-injury which precipitated their symptoms. Five patients complained of occasional night pain at the time of their last follow-up examination. Only one patient (who was re-injured) had to change professions as a result of shoulder symptoms. Posterior capsulorrhaphy for treatment of isolated posterior glenohumeral instability yields satisfactory clinical results. Recurrent instability in this series was associated with a specific re-injury and did not appear to increase with longer follow-up.     

The effect of radiofrequency energy on the length and temperature properties of the glenohumeral joint capsule

The purpose of this in vitro study was to evaluate the effect of radiofrequency energy on the length and temperature properties of the glenohumeral joint capsule in a sheep model. Dissected glenohumeral joint capsules were placed in a 37 degrees C tissue bath and treated with radiofrequency energy at temperature settings of 60 degrees, 65 degrees, 70 degrees, 75 degrees and 80 degrees C. Pretreatment and posttreatment tissue length was measured, and tissue temperature changes were recorded at distances of 0.0, 0.5, 1.0, 1.5 mm away from the probe path. Tissue shrinkage was found to be less than 4% for treatments below 65 degrees C, and increased to 14% for treatments at 80 degrees C. Posttreatment lengths of tissues treated at 65 degrees, 70 degrees, 75 degrees, 80 degrees C were significantly shorter than pretreatment lengths. The maximum tissue temperatures directly below the probe were observed to be 3.7 degrees to 6.7 degrees C lower than the set temperatures. As the distance from the probe was increased, the tissue temperature was found to decrease, reaching a value of less than 45 degrees C at 1.5 mm for all five treatment temperature settings. This study provided basic information on temperature settings, tissue shrinkage, and tissue temperature distribution of radiofrequency treatment.Arthroscopy 1998 May-Jun;14(4):395-400     

Quantitative assessment of glenohumeral translation

Cutaneous electromagnetic position sensors were used to quantify anteroposterior laxity of the shoulder. Forty-three female athletes were tested (27 were soccer players and 16 were swimmers). The athletes had a mean age of 18.8 years (range, 17-24 years), and all were free of shoulder disorders. Dominant and nondominant shoulders were tested. Each shoulder was suspended in 90 degrees abduction and neutral rotation. Serial anteroposterior translations were done manually similar to an anteroposterior drawer examination of the shoulder. The glenohumeral translation for the soccer players was 9.6 mm (range, 5.8-15.1 mm) in the dominant shoulder and 10.7 mm (range, 5.2-16.7 mm) in the nondominant shoulder. The translations in the swimmers were significantly greater at 12.4 mm (range, 8.9-15.9 mm) in the dominant and 13.8 mm (range, 8.8-17.4 mm) in the nondominant shoulders. The mean of the differences between the dominant and nondominant shoulders was 2.1 mm for the swimmers and soccer players. For the soccer players, the range for the side to side differences was 0.1 to 5.3 mm. For the swimmers, the range was 0.1 to 4.3 mm. Finding a clinical device for objective measurement of joint laxity in the shoulder that is accurate, reproducible, noninvasive, and easy to use has been evasive.     

Effect of selective capsulorrhaphy on the passive range of motion of the glenohumeral joint

BACKGROUND: Capsulorrhaphy of the glenohumeral joint is a common surgical procedure for the treatment of instability caused by increased capsular laxity. The effect of capsulorrhaphy on the range of motion of the shoulder is poorly understood. METHODS: We simulated localized capsular contractures by selective capsular plications in eight human cadaveric shoulders and studied the effect of such plications on the passive range of glenohumeral abduction, flexion, and external and internal rotation in different degrees of abduction. A 0.5 or 1-N-m torque was applied to the humerus, and the range of glenohumeral motion was measured with electronic goniometers in three planes and compared with those of the intact shoulder. RESULTS: Anterosuperior capsular plication most markedly affected external rotation of the adducted arm, decreasing it by a mean of 30.1 degrees (p < 0.0001). Anteroinferior plication significantly reduced abduction by a mean of 19.4 degrees (p < 0.0001) and external rotation by a mean of 20.6 degrees (p = 0.0046). Posterosuperior plication mostly limited internal rotation of the adducted arm (mean decrease, 16.1 degrees, p = 0.0045). On the average, total anterior and total posterior plication each limited flexion by approximately 20 degrees (p = 0.005) and abduction by >or=15 degrees (p < 0.005), whereas total anterior plication limited external rotation by >30 degrees (p 20 degrees (p < 0.0001). Total inferior capsular plication restricted abduction (by a mean of 27.7 degrees, p = 0.0001), flexion, and rotation. Total superior plication restricted external rotation and flexion. CONCLUSIONS AND CLINICAL RELEVANCE: Localized plications of the glenohumeral joint capsule lead to predictable patterns of loss of glenohumeral mobility. If plication is planned, losses of movement can be anticipated. The findings of this study may assist surgeons in identifying the parts of the capsule that are contracted and that may need lengthening.     

Axillary nerve temperatures during radiofrequency capsulorrhaphy of the shoulder

Purpose: The purpose of this study was to determine the temperatures along the course of the axillary nerve during radiofrequency (RF) capsulorrhaphy of the shoulder in a cadaver model. The hypothesis of this project was that temperatures capable of damaging neural tissue would be recorded during simulated RF capsulorrhaphy. Type of Study: Basic science evaluation. Methods: This study used 9 fresh-frozen cadaver shoulder capsules removed en bloc along with the underlying axillary nerve and soft tissue. The axillary nerve was instrumented with 4 thermocouples placed along the course of the nerve (2 thermocouples anterior and 2 posterior to the 6 o’clock position, spaced 7 mm apart). Each of the specimens underwent RF thermal capsulorrhaphy during which the temperature at each of the thermocouple positions was continuously recorded. Results: The average of the maximum temperature at each of the 4 positions measured along the course of the axillary nerve were 52.2 ± 18.0°C at the most anterior place probed, 45.8 ± 5.44°C (mid anterior), 44.5 ± 8.7°C (mid posterior), and 42.8 ± 10.1°C at the most posteriorly positioned probe. Two specimens had a maximum temperature greater than the 67°C set point of the device, and 7 specimens had a maximum temperature greater than 45°C in at least 1 thermocouple position. Conclusions: This study shows that heating of the axillary nerve can occur during RF capsular shrinkage of the shoulder and may potentially reach levels that can damage neural tissue.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 6 (July-August), 2001: pp 567–572     

Glenohumeral translation after arthroscopic thermal capsuloplasty with a radiofrequency probe

The purpose of this study was to determine whether there are changes in anterior and posterior glenohumeral translation after arthroscopic thermal capsuloplasty with a radiofrequency probe. Anteriorly directed loads of 15 N and 20 N were sequentially applied to the humerus of each of 5 cadaveric glenohumeral joints, and anterior translation on the glenoid was measured through use of a customized translation apparatus and an electromagnetic tracking device. The tests were then repeated with posteriorly directed forces, and posterior translation was measured. During testing, the glenoid was rigidly fixed and the glenohumeral joint was positioned to simulate 90 degrees of shoulder abduction and 90 degrees of external rotation. By means of the radiofrequency probe, thermal energy was then applied to the anteroinferior capsuloligamentous structures; anterior and posterior translation measurements were repeated. The results showed a significant reduction in anterior and posterior translations after thermal capsuloplasty (P < .05). Anterior translation decreased from 6.8 to 4.0 mm (a 41% decrease) with the 15-N load and from 8.6 to 4.9 mm (a 42% decrease) with the 20-N load. Posterior translation decreased from 9.3 to 5.8 mm (a 36% decrease) with the 15-N load and from 10.4 to 6.5 mm (a 35% decrease) with the 20-N load. The results of this study indicate that the radiofrequency probe can be used to decrease both anterior and posterior glenohumeral translation in vitro. The biological effect on heat-treated tissues over time needs to be studied to prove that this is a satisfactory treatment for glenohumeral instability.     

The glenohumeral micromotion and influence of the glenohumeral ligaments during axial rotation in varying abduction angle

BackgroundThe patients with shoulder instability or disorders in overhead athletes have been considered to have an abnormal micromotion at the glenohumeral joint. However, the normal range of the micromotion has not been available during axial rotation with various abduction angles, especially above 90° abduction. This study aimed to investigate the glenohumeral translation and influence of the glenohumeral ligaments during axial rotation with up to maximum abduction.MethodsFourteen healthy volunteers performed active axial rotations at 0°, 90°, 135°, and maximal abduction angles. The positions of the humeral head center relative to the glenoid at maximally external, neutral, and maximally internal rotations (ER, NR, IR, respectively) for each abduction angle were evaluated using two- (2D) and three-dimensional (3D) shape matching registration techniques. The shortest pathway and its length between the origin and insertion of the superior, middle, and inferior glenohumeral ligaments (SGHL, MGHL, and IGHL, respectively) were calculated for each position.ResultsThe glenohumeral joint showed 3.1 mm of superoinferior translation during axial rotation at 0° abduction (P < 0.0001), and 2.6 mm and 4.5 mm anteroposterior translation at 135° and maximal abduction (P < 0.0001), respectively. The SGHL and MGHL reached a maximum length at ER with 0° abduction, and the anterior and posterior bands of the IGHL reached a maximum at ER with 90° abduction and IR with 0° abduction.ConclusionsThese findings indicated that the SGHL played a role as an inferior suppressor at 0° abduction, while the anterior band of IGHL played a role as an anterior stabilizer at 90° abduction. Every glenohumeral ligament did not get taut and the anteroposterior translation became greater with increasing abduction angle, above 90°. These results could be used as a reference when comparing with the pathological shoulders in the future study.     

The effects of thermal capsulorrhaphy of medial parapatellar capsule on patellar lateral displacement

Background

The human femur is commonly considered as a subsystem of the locomotor apparatus with four conspicuous levels of organization. This phenomenon is the result of the evolution of the locomotor apparatus, which encompasses both constitutional and individual variability. The work therein reported, therefore, underlies the significance of observing anatomical system analysis of the proximal femur meta-epiphysis in normal conditions, according to the anatomic positioning with respect to the right or left side of the body, and the presence of system asymmetry in the meta-epiphysis structure, thus indicating structural and functional asymmetry.

Methods

A total of 160 femur bones of both sexes were compiled and a morphological study of 15 linear and angulated parameters of proximal femur epiphysis was produced, thus defining the linear/angulated size of tubular bones. The parameters were divided into linear and angulated groups, while maintaining the motion of the hip joint and transmission of stress to the unwanted parts of the limb. Furthermore, the straight and vertical diameters of the femoral head and the length of the femoral neck were also studied. The angle between the neck and diaphysis, the neck antiversion and angle of rotation of the femoral neck were subsequently measured. Finally, the condylo-diaphyseal angle with respect to the axis of extremity was determined. To visualize the force of intersystem ties, we have used the method of correlation galaxy construction.

Results

The absolute numeral values of each linear parameter were transformed to relative values. The values of superfluity coefficient for each parameter in the right and left femoral bone groups were estimated and Pearson's correlation coefficient has been calculated (> 0.60). Retrospectively, the observed results have confirmed the presence of functional asymmetry in the proximal femur meta-epiphysis. On the basis of compliance or insignificant difference in the confidence interval of the linear parameters, we have revealed, therefore, a discrepancy in values between the neck and the diaphysis angle and the angle of femoral neck rotation (range displacement of confident interval to a greater degree to the right).

Conclusion

This study assessed the observations of a systemic anatomical study encompassing the proximal femur meta-epiphysis behavior in normal condition. This work has significance in medical practice as the theoretical basis is also required in knowing the decreased frequency and degree of severity of osteoarthritic pathologies in the dominant lower extremity.     

The use of thermal capsulorrhaphy in the treatment of multidirectional instability

The purpose of this study is to report on our experience with thermal capsulorrhaphy in the treatment of multidirectional instability of the shoulder. Thirty-three consecutive patients (33 shoulders) with multidirectional instability were treated with arthroscopic thermal capsulorrhaphy. Twelve patients had a history of traumatic dislocation. Three patients had been previously treated with open inferior capsular shift procedures. At a mean follow-up of 36 months (range, 24-40 months), results were available for 30 patients. On the basis of the UCLA rating scale, out of a possible 35 points, the mean preoperative score was 16.7 points and postoperatively it was 30.1 points, with 3 excellent, 20 good, and 7 poor results. Twenty-three patients (76%) were returned to full activity. In our experience the majority of patients with multidirectional instability were able to return to their previous occupations in the armed forces following thermal capsulorrhaphy. More information further defining the biomechanical pathology of capsular laxity and the specific role of electrothermal shrinkage in treating shoulder instability is needed.     

The effect of capsular venting on glenohumeral laxity

Anesthetized shoulders are frequently stable against forces applied during drawer and sulcus tests, even though the shoulder muscles are inactive and do not contribute to stability. This passive stability is also evident in the glenohumeral joints of anatomic specimens. The translational laxity of anatomic specimen shoulders was measured, and it was demonstrated that this laxity was substantially increased when air was admitted into the capsule. Eight shoulders, aged 57-87 years, including six contralateral pairs, were analyzed using a six degrees-of-freedom force transducer and a six degrees-of-freedom spatial tracker. Capsules were vented by admitting air ad libitum through an 18-gauge needle. Venting reduced the force necessary to translate the humeral head with respect to the glenoid fossa by an average of 15.3 N (55%) for anterior forces, 10.8 N (43%) for posterior forces, and 19.0 N (57%) for inferior forces. It is likely that passive stability will also be diminished by a similar mechanism in patients with intact but excessively lax capsules. The principle of limited joint volume should be considered and tested when investigating glenohumeral stability.     

The effects of ACL deficiency on mediolateral translation and varus-valgus rotation

Background The anterior cruciate ligament (ACL) constrains the anterior translation and axial rotation of the tibia. However, the effect of ACL injury on the mediolateral translation and varus-valgus rotation of the tibia is unknown. Because of the oblique orientation of the ACL, we hypothesized that ACL deficiency alters mediolateral translation and varus-valgus rotation.

Methods The kinematics of 9 cadavers from full extension to 90° of flexion under various loading conditions were measured before and after ACL resection using a robotic testing system.

Results ACL deficiency increased the medial translation of the tibia and valgus rotation, especially at 15° and 30° of flexion. For example, at 15°, ACL deficiency increased the medial translation from 1.2 (SD 0.9) mm to 1.8 (SD 1.1) mm in response to a quadriceps load. The valgus rotation also increased from 0.8° (SD 0.6) to 1.7° (SD 0.8).

Interpretation ACL deficiency altered both the mediolateral tibial translation and valgus-varus rotation under various loading conditions. The increased medial tibial translation could shift the contact in the medial compartment towards the medial tibial spine, a region where degeneration is observed in ACL-deficient patients. In addition to restoring anterior laxity, ACL reconstruction might need to restore the mediolateral translation of the tibia and varus-valgus rotation of the knee.     

Cadaveric study of glenohumeral translation using electromagnetic sensors

Clinical methods for measuring shoulder translation rely heavily on the experience of the examiner and remain largely subjective, prone to errors of interobserver and intraobserver reproducibility. Accurate in vitro methods of measuring glenohumeral translation exist. The purpose of the current study was to evaluate the accuracy of computerized electromagnetic spatial sensors applied to the skin, in measuring glenohumeral translation under simulated conditions of a standard shoulder examination. Seven thawed, fresh-frozen shoulder specimens from cadavers were used in the study. Soft tissue and skin were not removed. The specimens were mounted to simulate clinical positions of patients having an anteroposterior drawer or load-and-shift test. A series of anterior and posterior displacements were done manually under two conditions. Condition I: Electromagnetic position sensors were taped to skin and held beneath the examiner's fingers; and Condition II: Sensors were fixed rigidly to pins inserted into the glenoid and humeral head, respectively. Displacement values between conditions, within trials, and among specimens were compared for accuracy and reproducibility. Strong agreement was shown between Condition I and Condition II for the anterior and posterior directions (interclass correlation coefficients 0.81 and 0.86, respectively). Simple linear regression revealed a significant association between conditions in the anterior and posterior directions. Reproducibility between trials under each condition was extremely high, with interclass correlation coefficients greater than or equal to 0.98 regardless of direction of displacement or testing condition. The data from the current study show that cutaneous application of electromagnetic position sensors to the shoulder can accurately and reproducibly measure true glenohumeral translation under testing conditions that mimic a standard, clinical shoulder examination.     

The effect of shoulder position on inferior glenohumeral mobilization

Study Design

Cross-sectional clinical measurement study.

Superoinferior translation in the intact and vented glenohumeral joint

The purpose of this investigation was to measure inferior translation in the intact and vented shoulder in different positions of abduction and rotation. Fifteen shoulders from adult cadavers were tested before and after venting of the joint capsule on an apparatus that permitted unconstrained translation when a 50 N inferior force was applied to the humeral shaft. The greatest inferior translation in the intact shoulder occurred at 45° abduction in neutral rotation. Venting the capsule significantly increased inferior translation in all positions but 45° abduction, and the greatest effect was seen at 0° glenohumeral abduction in neutral rotation. The so-called "sulcus sign" is the result of intraarficular vacuum effect and capsular laxity. Venting the capsule results in a significant increase in inferior translation. This is an important effect to consider during procedures for repairing instability of the shoulder, because failure to appreciate the normal "play" in inferior glenohumeral translation might lead the surgeon to believe that perceived laxity represents actual instability.     

The use of arthroscopic thermal capsulorrhaphy to treat internal impingement in baseball players

Purpose: To determine if reducing glenohumeral translation by arthroscopic thermal shrinkage would improve the results of arthroscopic treatment of internal impingement in baseball players. Type of Study: Retrospective review. Introduction: Traditional treatment of internal impingement does not address the pathophysiology. Baseball players’ shoulders routinely have glenohumeral laxity. Addressing this laxity by thermal capsulorrhaphy may improve the results in the treatment of these patients. Traditional treatment of labral and rotator cuff debridement and/or repair has had marginal results in regard to the most important criterion, return to competition. Methods: Charts of all patients undergoing surgical arthroscopy of the shoulder for suspected internal impingement were analyzed. Patients were divided into 2 groups: traditional treatment (non–heat-probe group, NHP, n = 51) or traditional treatment plus thermal capsulorrhaphy (heat-probe group, HP, n = 31). Internal impingement was confirmed by physical examination and arthroscopic criteria. All participants were baseball players and follow-up was 30 months. Data were analyzed for initial return to play and continued participation 30 months after surgery. Results: Mean time for return to competition was 7.2 months in the NHP group and 8.4 months in the HP group; 80% of the NHP group returned to competition compared with 93% of the HP group. At 30 months after surgery, 67% of the NHP group was back to competition compared with 90% of the HP group (P =.01). The HP group averaged 7° less external rotation than before surgery. There were no significant complications in either group. Conclusions: Thermal capsular shrinkage can be safely used in the treatment of internal impingement in the throwing athlete.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 6 (July-August), 2001: pp 573–577     

Stabilisation of a posteriorly unstable glenohumeral joint during total shoulder arthroplasty: A novel capsulorrhaphy technique

Restoration of the soft tissue balance is of great importance during shoulder arthroplasty. We report a novel technique of posterior capsulorrhaphy through an anterior approach for the management of intraoperative posterior instability during implantation of the prosthesis. After the operation, the patients were able to follow a rehabilitation program with some minor restrictions, avoiding the necessity of a shoulder spica or other constrictive measures. This technique is simple, safe and sufficient to address instability due to abundance of the posterior shoulder capsule.