Shoulder proprioception - lessons we learned from idiopathic frozen shoulder.

BACKGROUND: Of all the most frequent soft tissue disorders of the shoulder, idiopathic frozen shoulder (IFS) offers the greatest potential for studying proprioception. Studies concerning the presence of proprioception dysfunctions have failed to determine the potential for spontaneous healing of passive shoulder stabilizers (anterior and posterior capsule, middle and inferior gleno-humeral ligaments), its relationship with passive (PJPS) and active (AJPS) shoulder proprioception for internal and external rotation (IR, ER), as well as the isokinetic muscle performance of the internal and external rotators. This study investigates these dependencies in the case of arthroscopic release of IFS. METHODS: The study group comprised 23 patients (average aged 54.2) who underwent arthroscopic release due to IFS and 20 healthy volunteers. The average follow-up time was 29.2 months. The Biodex system was used for proprioception measurement in a modified neutral arm position and isokinetic evaluation. The results were analysed using the T-test, Wilcoxon and interclass correlation coefficient. P-values lower than 0.05 were considered significant. RESULTS: Statistically significant differences were found between involved (I) and uninvolved (U) shoulders only in the cases of PJPS and AJPS, peak torque, time to peak torque and acceleration time for ER (p < 0.05). No statistically significant difference was noted between PJPS IR and PJPS ER or between AJPS IR and AJPS ER (p > 0.05) for the U shoulders. CONCLUSIONS: The anatomical structure of anterior (capsule, middle and anterior band of inferior gleno-humeral ligament) and posterior (capsule and posterior band of inferior gleno-humeral ligament) passive shoulder restraints has no impact on the difference in PJPS values between ER and IR in a modified neutral shoulder position. The potential for spontaneous healing of the anterior and posterior passive shoulder restraints influences PJPS recovery after arthroscopic release of IFS. ER peak torque deficits negatively affect AJPS values. PJPS and AJPS of ER and IR can be measured with a high level of reproducibility using an isokinetic dynamometer with the arm in a modified neutral shoulder position. Differences greater than 15 % for PJPS and >24 % for AJPS for ER and IR can be helpful for future studies as baseline data for identification of particular passive and active shoulder stabilizers at risk.

Is resection of the tendon edge necessary to enhance the healing process? An evaluation of the expression of collagen type I, IL-1ß, IFN-γ, IL-4, and IL-13 in the distal 1 cm of a torn supraspinatus tendon: part II.

BACKGROUND: Type I collagen proin pro-in expression in a damaged supraspinatus tendon is thought to be dependent on the distance from the edge of the tear and the local expression of pro-inflammatory, anti-proliferative, and pro-proliferative cytokines. The study evaluates the expression of type I collagen, pro-inflammatory interleukin (IL) 1ß, anti-proliferative interferon-γ (IFN-γ), and pro-proliferative IL-4 and IL-13 cytokines along a 1-cm section taken from the edge of a torn supraspinatus tendon. Three sections were taken: 3 mm distal to the tear, 3 mm proximal to the tear, and the 4-mm middle section between them. METHODS: Nine patients (average age, 58 years) were included in the study. All fulfilled strict inclusion criteria regarding tear morphology and reconstruction technique. Samples were taken from the ruptured supraspinatus tendon at the time of arthroscopic repair. Quantitative real-time polymerase chain reaction assay was used for analysis. RESULTS: The expression of type I collagen, IL-4, and IL-13 significantly increased and that of IL-1ß and IFN-γ decreased from the distal to the proximal parts of the tendon edge (P < .05). CONCLUSIONS: The expression of type I collagen is dependent on the distance from the edge of the torn supraspinatus tendon, the balance between anti-proliferative IFN-γ and pro-proliferative IL-4 and IL-13, and the expression of pro-inflammatory IL-1ß. Hence, whereas resection of the distal 3 mm of the torn supraspinatus tendon edge eliminates its least valuable part, resection between 4 and 7 mm may enhance the healing process by reaching a reasonable compromise between the mechanical features of the tendon characterized by collagen type I expression and the technical abilities of reconstruction.

Is resection of the tendon edge necessary to enhance the healing process? An evaluation of the homeostasis of apoptotic and inflammatory processes in the distal 1 cm of a torn supraspinatus tendon: part I.

BACKGROUND: We hypothesize that the expression of proapoptotic and antiapoptotic molecules and cytokines is dependent on the distance from the torn supraspinatus tendon edge and this expression may influence its potential for healing. The aim of this work is to evaluate the expression of proapoptotic Bax molecule and caspases 3, 8, and 9; antiapoptotic Bcl-2 molecule; and proinflammatory tumor necrosis factor (TNF) α and anti-inflammatory interleukin 10 (IL-10) in 3 sections taken from a 1-cm section of the edge of a torn supraspinatus tendon: 3 mm distal and 3 mm proximal, as well as the remaining 4-mm middle section between them. METHODS: Nine patients, with a mean age of 58 years, were included in the study. All fulfilled strict inclusion criteria regarding the morphology of the tear and reconstruction technique. Samples were taken from the ruptured supraspinatus tendon at the time of arthroscopic repair. Quantitative real-time polymerase chain reaction assay was used for analysis. RESULTS: The expression of caspases 9, 8 and 3; Bax; and TNF-α significantly decreased from the distal to the proximal parts of the tendon edge (P < .05). However, a significant increase in Bcl-2 and IL-10 expression was also found in the same direction (P < .05). CONCLUSIONS: Tenocytes can reduce the expression of proapoptotic caspases 3, 8, and 9 and Bax, as well as proinflammatory TNF-α, by increasing the expression of Bcl-2 and IL-10 within 1 cm of the supraspinatus edge in a distal to proximal direction. Resection 4 to 7 mm from the edge of the torn supraspinatus tendon may enhance the healing process by reaching a reasonable compromise between molecular homeostasis of apoptotic and inflammatory processes and mechanical aspects of rotator cuff reconstruction.

The evaluation of the influence of selected patellofemoral joint geometry indicators observed in magnetic resonance imaging on the incidence of anterior knee pain in patients after anterior cruciate ligament reconstruction using hamstrings.

BACKGROUND: Anterior knee pain (AKP) is a frequent serious clinical problem after anterior cruciate ligament (ACL) reconstruction, regardless of the graft material used. The author conducted prospective studies of the correlation between AKP and disturbed geometry of patello-femoral joint observed in magnetic resonance imaging (MRI), in patients with injured ACL reconstructed with the use of hamstrings. MATERIAL AND METHODS: The study included 60 patients (34 males and 26 females), at the mean age of 31, who underwent ACL reconstruction with flexors. Only patients without clinical AKP symptoms or AKP factors after reconstruction were included in the study. Before surgery, in all patients MRI was performed in order to evaluate the patellar height, excessive patellar pressure (EPP) and patellar lateralization (PL). In the postoperative course, AKP and its correlation with the ratios mentioned above were observed. RESULTS: In the group of patients included in the study, pathological patellar height was not observed, EPP was diagnosed in 15%, PL in 13.3% and EPP and PL jointly in 11.9% of the patients. AKP was observed in 8 out of 9 patients with abnormal lateral pressure, 7 patients with EPP and 7 patients with concomitant excessive lateral pressure and PL. The first symptoms of AKP appeared between the seventh and twelfth week after surgery and increased after 12 weeks. CONCLUSIONS: The occurrence of excessive lateral pressure syndrom (EPP) and PL confirmed in MRI was very strongly correlated (89% and 100%, respectively) with the occurrence of AKP after ACL reconstruction. The evaluation of the patellofemoral joint geometry, taking into account the EPP and PL ratios in pre-operative magnetic resonance image (MRI) in patients with injured anterior cruciate ligament, may allow us to establish the AKP risk group and administer suitable preventive treatment (prophylaxis).

0.25 mm calibration and its impact on bone tunnel surface area in anterior cruciate ligament reconstruction with hamstrings. Preliminary report.

BACKGROUND: We evaluated the clinical possibility of using 0.25 mm calibration and its effect on bone tunnel surface areas of varied length in comparison to the standardized graft calibration by every 0.5 mm in case of ACL reconstruction with hamstrings. MATERIAL/METHODS: The ACL reconstruction with hamstrings were done in 30 patients aged 18 to 28 years.The inclusion criteria were the graft diameter between 7-8.5 mm with its calibration by every 0.5 mm. and the length of the femoral tunnel minimum 4 cm. The calculation of surface area of a bone tunnels length ranging from 2.5 to 5 cm was done. RESULTS: 0.25 mm decrease in bone-tunnel diameter was possible in 56.7% of cases and decreased tunnel surface area of 3.4% in relation to primary value of graft diameter calibrated by every 0.5 mm, irrespective of its length. 0.5 cm change of bone tunnel length from 2.5 cm to 5 cm results in surface area increase of 17% (3 cm), 37.5% (4 cm) and 50% (5 cm) respectively, regardless of calibration rate. CONCLUSIONS: 0.25 mm reduction of bone tunnel diameter in relation to graft one calibrated by every 0.5 mm changes its surface area of 3.4%, regardless of tunnel length within range of 2.5-5 cm. Change of tunnel length from 2.5 to 3, 4 and 5 cm increase surface area by 17, 38 and 50% respectively, regardless of its diameter within range of 6.75-8.5 mm with 0.25 mm calibration rate. The 0.25 mm bone tunnel calibration should be a standard option in ACL reconstruction with hamstrings.