Can we accelerate rehabilitation following reverse shoulder arthroplasty? A systematic review.

Background: There is no consensus concerning the rehabilitation protocol following reverse shoulder arthroplasty. Several patients are expecting to be able to use their arms for sports or recreation shortly after their operation. Methods: This review was designed as an intervention systematic review with narrative analysis. Authors searched English literature in PubMed and Embase databases from 1/1/1989 until July 2022. Controlled studies comparing rehabilitation protocols for patients undergoing reverse shoulder arthroplasty were included. Data quality was examined with the Cochrane risk of a bias assessment tool for randomized trials, the Methodological Index for Non-Randomized studies (MINORS) tool, as well as the Grading of Recommendations Assessment Development and Evaluation (GRADE) approach. Results: Three studies were finally analyzed. At 3 months post-op, forward flexion was found to be significantly higher in the early rehabilitation group (140.5, 95% confidence intervals (CIs): 135.10-145.89; the delayed rehabilitation group mean was 131.24, 95% CI: 125.73-136.74; p = 0.019). Twelve months post-op, no significant difference in any clinical or patient-reported outcome was shown. More complications were reported in the 6 weeks-delayed rehabilitation group. Discussion: Newer regimes permit immediate shoulder mobilization but may not be applied to every patient. The lack of strong evidence warrants the need for future controlled studies; subsequently, postoperative rehabilitation should be individualized.

Medial patellofemoral ligament reconstruction using an endobutton device: A narrative review.

Since the recognition of MPFL as the primary soft-tissue restraint to lateral displacement of the patella, its reconstruction gained popularity either alone or in combination with other procedures. Today, although there are plenty of techniques described in the literature, there is no consensus regarding which one is better. MPFL reconstruction using an endobutton device has been proved to be a reliable option with satisfying clinical results. Single or dual tunnel can be done depending on surgeon's preference. For safer outcomes more randomized controlled trials should be done while authors should be more meticulous when it comes to surgical technique.

Mechanisms of shoulder trauma: Current concepts.

Acute traumatic injuries to the glenohumeral articulation are common. The types of injuries depend on age, muscle strength, bone density, and biomechanics of the traumatic event. Understanding the different mechanisms of trauma and how they affect the functional anatomical structures of the shoulder joint is crucial for the treatment of these lesions. Therefore, when clinicians have knowledge of these mechanisms they can accurately diagnose and treat shoulder pathology and predict distinct injury patterns. Here, we have described the fundamentals of the mechanisms of injury of the glenohumeral dislocation, dislocation with fracture of the humeral head, and the proximal humerus fracture. We have focused on common injury mechanisms and the correlation with radiological diagnostics. Radiological and laboratory findings of distinct types of injury were also discussed.

Arthroscopic Modified Elbow Lateral Collateral Ligament Imbrication: An Operative Technique.

When the lateral collateral ligament (LCL) complex fails to support the radiocapitellar and ulnohumeral joints in advanced stages of insufficiency, the patient experiences posterolateral rotatory instability (PLRI). Open lateral ulnar collateral ligament repair with a ligamentous graft has been the standard treatment for PLRI. Despite producing good clinical stability rates, this method is associated with significant lateral soft-tissue dissection and a lengthy recovery period. By fastening the LCL to its humeral insertion, arthroscopic imbrication of the LCL can increase stability. The senior author modified this technique. With the aid of a passer, the LCL complex, lateral capsule, and anconeus may be weaved with a single (doubled) suture, secured with a Nice knot. LCL complex imbrication may be used to restore stability and improve pain and function in patients with grade I and II PLRI.

Medial patellofemoral ligament reconstruction using patella bone tunnel techniques with or without implants. A systematic review of outcomes and complications.

PURPOSE: Τhe main goal of this study was to compare the clinical results, including the complication rates and patient-reported outcomes, in patients who underwent surgery for recurrent patellar dislocation using different patellar tunnel fixation techniques. This study compared Medial Patellofemoral Ligament (MPFL) reconstruction implant free techniques against ones that used implants. METHODS: The present systematic review was conducted according to the PRISMA guidelines. The literature search was conducted in January 2023. We included patients who underwent isolated MPFL reconstruction for recurrent patellar instability. Patients with confirmed concomitant or prior ipsilateral knee procedures, multiligament injury, severe patellar dysplasia or less than 6 months of follow-up were excluded. MINORS and MCMS scores were used for the assessment of methodological quality. RESULTS: Data from 750 procedures were collected, of which 284 used implants to perform the procedure while in 455 an implant-free technique was used. Patient age at the time of surgery ranged from 11 to 60 years while the follow-up time of the studies ranged between 3 and 108 months. Postoperative Kujala (0.3, p = 0.89) and Lysholm (1.2, p = 0.26) scores were better in the implant-free techniques compared to implant-based. A higher rate of recurrent dislocation (OR 0.51; 95% CI 0.10-2.54, p = 0.4), subluxation (OR 0.20; 95% CI 0.40-0.88, p = 0.019) and stiffness (OR 0.76; 95% CI 0.33-1.72, p = 0.55) was noted in the implant-free techniques, while the implant-based techniques displayed increased incidence of patella fractures (OR 3.12; 95% CI 0.77-12.6, p = 0.09), reoperation (OR 1.69; 95% CI 0.78-3.65, p = 0.17) and infection (OR 2.07; 95% CI 0.46-9.32, p = 0.33). CONCLUSION: There was no significant difference between the 2 techniques in terms of patient reported outcomes. Regarding complications, MPFL reconstruction using implants demonstrated significant higher rate of patella fractures while the implant free technique showed a greater risk of subluxation.

Evaluation of gait recovery after total knee arthroplasty using wearable inertial sensors: A systematic review.

PURPOSE: This study aimed to conduct a systematic review of the recent research output to present more evidence of the current clinical applications of wearable sensors to determine the change and the recovery in gait function pre- and post-total knee arthroplasty (TKA). METHODS: A systematic search of the PubMed, ScienceDirect, and Scopus databases was conducted in October 2022. Inclusion criteria consisted of applying acceleration wearable sensors for pre- and post-arthroplasty assessment of the gait cycle. Studies reporting gait analysis using wearable sensors in patients with knee osteoarthritis at any time after total or partial knee arthroplasty (KA) were also included. Each included study was assessed using the Joanna Briggs Institute Critical Appraisal Tool for Quasi-Experimental studies. RESULTS: Twelve articles were finally considered. The extracted data included essential characteristics of participants, KA studies and their characteristics, sensor technology characteristics and the clinical protocols, gait parameter changes, and various clinical outcome scores at different follow up times after KA. Postoperative examinations were performed from 5 days to 1 year after KA. Clinical outcome scores and gait variables for all patient groups, with or without postoperative rehabilitation, showed various recovery profiles. A variety of wireless sensor devices for gait analysis were recorded. Also, different types of KA were found in the studies. CONCLUSIONS: The study's findings showed that acceleration-based gait analysis has notable clinical use in monitoring patients after KA. This application provides objective information on the functional outcome beyond the use of clinical outcome scores. More extensive prospective studies are required to investigate gait function further with the help of wearable sensors in patients with knee osteoarthritis.

Endoscopic-Assisted Hamstring Tendon Harvesting.

Efficient hamstring tendon harvesting is a crucial part of anterior cruciate ligament reconstruction surgery using autografts. Harvesting of the gracilis and semitendinosus tendons is usually performed using an open approach, exposing the distal tibial attachment of the tendons at the pes anserinus and proceeding using a tendon stripper without direct tendon visualization. The success of the anterior cruciate ligament reconstruction surgery strongly depends, among other factors, on the preservation of the hamstring tendon length and integrity. Inadequate tendon release from their attachments and improper use of the tendon stripper, in addition to poor intraoperative visibility, may lead to premature tendon amputation, endangering the success of the operation. We describe an endoscopic-assisted technique of hamstring tendon harvesting that provides complete visualization of the tendons from the tibia attachment to the musculotendinous junction. The procurement of the tendons is completed under direct vision using any tendon stripper. This surgical technique offers a way to minimize complications that may arise during the standard open tendon harvesting techniques without additional visualization.

Morphometric MRI Evaluation of Three Autografts Used in Anterior Cruciate Ligament Reconstruction in Athletes.

The purpose of the present study was to quantify the morphometric characteristics of three tendon autografts (hamstring tendons (HT), quadriceps tendon (QT), and patellar tendon (PT)) used in anterior cruciate ligament (ACL) reconstruction. For this purpose, knee magnetic resonance imaging (MRI) was obtained in 100 consecutive patients (50 males and 50 females) with an acute, isolated ACL tear without any other knee pathology were used. The level of the physical activity of the participants was determined using the Tegner scale. Measurements of the tendons' dimensions (PT and QT tendon length, perimeter, cross-sectional area (CSA), and maximum mediolateral and anteroposterior dimensions) were performed perpendicular to their long axes. Higher values were recorded as regards the mean perimeter and CSA of the QT in comparison with the PT and the HT (perimeter QT: 96.52 ± 30.43 mm vs. PT: 63.87 ± 8.45 mm, HT: 28.01 ± 3.73 mm, F = 404.629, p < 0.001; CSA QT: 231.88 ± 92.82 mm2 vs. PT: 108.35 ± 28.98 mm2, HT: 26.42 ± 7.15 mm2, F = 342.415, p < 0.001). The length of the PT was shorter in comparison with the QT (53.1 ± 7.8 vs. 71.7 ± 8.6 mm, respectively, t = -11.243, p < 0.001). The three tendons showed significant differences in relation to sex, tendon type, and position as regards the perimeter, CSA, and the mediolateral dimensions but not for the maximum anteroposterior dimension.

Biomolecules Related to Rotator Cuff Pain: A Scoping Review.

The pathophysiology of pain in patients suffering from rotator cuff (RC) tendinopathy or tears has been examined in various ways. Several molecules from tissue samples taken from the subacromial bursa, supraspinatus tendon, glenohumeral joint fluid, and synovium as well as from peripheral blood have been investigated. This article explores these studies, the assessed biomarkers, and groups their results according to the status of tendon integrity (tendinopathy or tear). Through a structured PubMed database search, 9 out of 658 articles were reviewed. Interleukins, mostly IL-1b and its antagonist, IL-1ra, matrix Metalloproteinases (MMPs), the vascular endothelial growth factor (VEGF) and TNF-a are biomarkers directly searched for correlation to pain level. Most studies agree that IL-1b is directly positively correlated to the degree of pain in patients with RC tendinopathy, especially when the examined sample is taken from the subacromial bursa. VEGF, and TNF-a have been related to shoulder pain preoperatively and TNF-a has also been linked with sleep disturbance. Further studies pointing to more biomarkers taken from the subacromial bursa or tendon directly relating to pain degree are warranted.

Modified Graft Loop Technique Augmented With Nonabsorbable Suture Tape for Chronic Elbow Dislocation.

The task of achieving a good clinical outcome on patients with chronic elbow dislocation is arduous. Any stabilization method used should be robust enough in order to allow for early elbow motion. Immobilization of the elbow for a prolonged time period may lead to stiffness and heterotopic ossification. Several methods of ligament reconstruction have tried to address the global instability that is present in such scenarios. We describe a technique of reconstructing both bands of the medial ligament, and the lateral ulnar collateral ligament of the elbow, by using a looped tendon graft and reinforcing the lateral side with nonabsorbable tape and anchors. The graft is passed as a loop once through the humerus and ulna, recreating the anterior portion of the medial collateral ligament and the lateral ulnar collateral ligament. Then the lateral side is augmented with the tape and anchors and the loop is fixed. Lastly, the medial tail of the graft is used in order to recreate the posterior part of the medial ligament. This technique uses a single graft along with nonabsorbable tape and anchors to make a robust construct that will withstand early range of motion, without jeopardizing elbow stability. Potential complications include damage to the ulnar nerve, infection, elbow stiffness, or persistent instability in complex cases with bone involvement.

Giant Cell Tumor of the Patellar Tendon Sheath Mimicking a Meniscal Tear in Athletes.A Report of Two Cases.

Introduction: Giant cell tumors(GCT) are uncommon and benign tumors originating due to proliferation of the tendon synovial sheath. Most commonly are located in the fingers. Involvement of the patellar tendon in the knee is extremely rare. Case Report: We report two cases who presented with moderate swelling located in the anterior surface of the knee, localized anterior knee pain, and painful loss of flexion and catching and locking symptoms. Following detailed imaging evaluation, both cases were treated with open surgical excision and patellar tendon synovectomy. Histological examination revealed the presence of a giant cell tumor of the patellar tendon sheath in both cases. Conclusion: Despite the rarity to GCT, the importance of considering all possible tumors in cases where a soft-tissue tumor is present should be stressed out.

Acromioclavicular joint arthritis is not an indication for routine distal clavicle excision in arthroscopic rotator cuff repair.

PURPOSE: To evaluate the significance of untreated primary acromioclavicular joint (ACJ) osteoarthritis, encountered during arthroscopic rotator cuff repair (RCR), as a cause of persistent symptomatology and need for revision surgery. METHODS: In a cohort of 811 consecutive patients older than 55 years who underwent RCR, the effect of primary ACJ osteoarthritis presence was prospectively examined. A total of 497 patients with mild/moderate and severe ACJ osteoarthritis based on preoperative MRI evaluation were allocated to Group A (n = 185, symptomatic ACJ) and Group B (n = 312, asymptomatic ACJ). Distal clavicle excision was not performed regardless of the presence of pain. The minimum follow-up was 28 months (28-46). The visual analogue scale (VAS) pain scores were assessed for ACJ pain on palpation, the cross body adduction test, the Constant-Murley, and the American Shoulder and Elbow Surgeons (ASES). RESULTS: The overall loss to follow-up rate was 3.82% (19 patients: 11 in Group A and eight in Group B). The mean ASES score at the latest follow-up was 91.16 ± 9.3 and 92.37 ± 10.44 in Groups A and B, respectively, and the mean Constant-Murley score was 96.36 ± 5.7 and 95.76 ± 4.6 in Groups A and B, respectively. There was no statistical significance between regarding both scores. Localised ACJ pain on palpation and pain on cross body adduction were diminished in both the symptomatic and asymptomatic group. There were five cases (1%: two in Group A and three in Group B) with persistent ACJ pain who had failed the conservative treatment, and ACJ excision was necessary to alleviate the symptoms. All revision operations were uncomplicated with symptom resolution. CONCLUSION: Untreated ACJ osteoarthritis, symptomatic or not, encountered during arthroscopic RCR is associated with a low percentage of failure. Routine distal clavicle excision is not absolutely necessary, even in patients with symptomatic ACJ osteoarthritis. LEVEL OF EVIDENCE: II, Prospective cohort study.

Ultrasound-guided versus palpation-guided corticosteroid injections for tendinosis of the long head of the biceps: A randomized comparative study.

PURPOSE: To compare accuracy, patient discomfort, and clinical outcome of ultrasound-guided versus palpation-guided corticosteroid injections to the bicipital groove in patients with long head of biceps (LHB) tendinosis. MATERIALS AND METHODS: Forty-four patients with primary LHB tendinosis were randomized into two groups (group A, n = 22; group B, n = 22). All patients underwent treatment with a single corticosteroid injection to the bicipital groove. Injections in group A were performed under ultrasound-guidance, while in group B using a palpation-guided technique. The duration of each procedure was recorded. To assess accuracy, ultrasound examination was performed in both groups after injection. Patient discomfort was evaluated with visual analogue scale (VAS) for pain. The clinical outcome was assessed comparing the VAS, the Single Assessment Numeric Evaluation (SANE) score and the QuickDASH score before treatment and after 4 weeks and 6 months. RESULTS: The mean duration of the procedure was 64 ± 6.87 s in group A and 81.91 ± 8.42 s in group B (p < 0.001). Injection accuracy in group A was 100% and in group B 68.18%. Discomfort was lower in group A, as compared to group B (22.10 vs. 35.50; p < 0.001). Symptoms, as measured by VAS, SANE and QuickDASH scores, improved in both groups at 4 weeks and 6 months (p < 0.05). Superior clinical improvement was recorded in group A in both time points (p < 0.05). CONCLUSIONS: Corticosteroid injections are an effective treatment for primary LHB tendinosis. Under ultrasound guidance, injections to the bicipital groove are faster and produce lower discomfort. Superior accuracy and clinical outcomes can be achieved using the ultrasound-guided technique. LEVEL OF EVIDENCE: Level II; Prospective Randomized Comparative Study.

Osteoid osteoma of the radial styloid mimicking wrist arthritis: a case study.

Osteoid osteoma in the wrist and hand region is an uncommon but severely symptomatic primary bone tumour. We report the case of a professional athlete with a radial styloid osteoid osteoma who presented with significant wrist pain and stiffness resembling arthritis for which she was treated initially. The symptoms started after a fall on the outstretched hand and significant delay in the diagnosis occurred. Following detailed imaging evaluation of the tumour site excision biopsy was curative.

The morphologic variations of low and high hip dislocation.

UNLABELLED: Three different types of congenital hip disease in adults have been distinguished based upon the position of the femoral head relative to the acetabulum and the underlying pathoanatomy of the joint: (1) dysplasia; (2) low dislocation; and (3) high dislocation. To facilitate classification of borderline or ambiguous cases, we studied the morphologic variations of low and high dislocation as observed on the radiographs of 101 hips with low and 74 hips with high dislocation. In low dislocation, 54 hips (53.5%) had extended coverage of the true acetabulum (Type B1) and 47 hips (46.5%) had limited coverage (Type B2). Among the cases with high dislocation, a false acetabulum with an adjacent femoral head occurred in 46 hips (62.2%) (Type C1), and the femoral head was floating within the gluteal muscles in 28 hips (37.8%) (Type C2). The kappa value for interobserver agreement between two raters who made radiographic measurements was 0.963, and for intraobserver agreement between the two evaluations of the same observer it was 0.946 and 0.971, respectively. The two types of low and high dislocation were associated with high intra- and interobserver agreement. Whether these distinctions have clinical utility requires further validation. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Severe upper limb injuries with or without neurovascular compromise in children and adolescents--analysis of 32 cases.

The healing and regeneration capacity of the injured tissues in childhood, adolescence, and adult life differs significantly. As a result, the prognosis of compound injuries of the upper limb in different age groups varies; therefore, the decision making and management of these cases should be age-specific. This article presents a series of 32 patients aged 1.5-14 years, with compound injuries of the upper limb that have been treated in our hospital during the period of the last 6 years. Ten of the above cases involved major vascular lesions that required revascularization or replantation. The injuries were classified according to the SATT (Severity, Anatomy, Topography, Type) classification system. This study shows that the outcome of compound upper limb injuries is age-related, while the SATT classification system is a valuable tool in the decision making process. Further research should be undertaken to determine age group-specific indications for the management of compound upper limb injuries, based on the SATT classification system.

The biomechanical capacity of the periosteum in intact long bones.

INTRODUCTION: The biological function of the periosteum is profusely described but its contribution to the biomechanical properties of the bone has been considered negligible. The purpose of this study was to examine the biomechanical properties of periosteum-preserved long bones. MATERIALS AND METHODS: The biomechanical properties of both femora and tibiae of 30 male, 4-month-old Wistar rats were evaluated using a destructive three-point-bending testing protocol. In both bones from one side the periosteum was preserved, while in the contralateral bones the periosteum was stripped off. Ultimate strength, stiffness, energy absorption and deflection were derived automatically from the load-deformation curve recorded for each bone. RESULTS: As regards the femur, the periosteum-covered bones displayed statistically significant higher values for all parameters measured compared to the periosteum-stripped bones. Ultimate strength, stiffness, absorbed energy and deflection of stripped and periosteum-covered femora were, respectively, 146.76 +/- 44.71 and 196.01 +/- 41.47 N, 44.25 +/- 17.35 and 61.62 +/- 15.07 N/mm, 0.00054 +/- 0.00274 and 0.00011 +/- 0.00354 Nmm, 0.67 +/- 0.25 and 1.07 +/- 0.28 mm. In the tibia, only energy absorption (0.00353 +/- 0.00199 and 0.0010 +/- 0.00339 Nmm) and deflection (1.71 +/- 0.56 and 0.86 +/- 0.36 mm) were significantly higher in the periosteum-covered bones. The pattern of bone failure was also different in the two groups. In periosteum-covered bones the two bone parts remained in close apposition stabilized by the periosteal membrane, while in a few cases the periosteum was stretched or torn opposite the loading site. CONCLUSION: The periosteum not only has significant biological function but also provides mechanical support to the bone and amplifies the biomechanical capacity of intact rat long bones in bending, probably taking advantage of its fibrous and elastic properties.

A comparison of the spectrum of intra-articular lesions in acute and chronic anterior shoulder instability.

PURPOSE: The purpose of the study was to compare the incidence of secondary intra-articular shoulder lesions in patients with acute and chronic anterior shoulder instability. The occurrence of glenoid shape alterations (inverted pear glenoid) in recurrent instability was especially examined. METHODS: Data for all arthroscopically ascertained intra-articular shoulder lesions in a series of 127 patients with acute and chronic traumatic anterior instability were recorded. RESULTS: Hemarthrosis was evident in all patients with acute dislocation and in 7 patients with chronic laxity who underwent surgery shortly after a dislocation episode. In both groups the presence of a chondral or osteochondral Hill-Sachs lesion was noted in 112 patients (88.1%), a Bankart lesion was noted in 106 patients (83.46%), an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion was noted in 13 patients (10.23%), a SLAP lesion was noted in 26 patients (20.47%), a humeral avulsion of the glenohumeral ligament (HAGL) lesion was noted in 2 acutely dislocated shoulders (1.57%), and capsular laxity was noted in 33 patients (25.98%). All ALPSA lesions were noted in patients with chronic instability (P = .044), and both HAGL lesions were found in patients with acute dislocations (P = .002). In patients with acute dislocations the incidence of Bankart lesions was 78.2% (18/23), whereas in chronic cases the incidence of Bankart or ALPSA lesions was 97.11% (101/104) (P = .002). In the group with acute dislocations there was a Hill-Sachs lesion in 15 cases (65.21%) and chronic recurrent instability accounted for 97 cases (93.26%) (P = .001). The capsule was considered lax in 2 patients with acute instability and 31 patients with chronic instability (8.69% v 29.8%, P = .037). The overall frequency of SLAP lesions was not statistically significant between acute and chronic cases (P = .868), unlike their distribution. In acute cases there were 3 type I and 2 type II SLAP lesions, whereas in chronic cases there were 4 type I, 13 type II, 3 type III, and 1 type IV SLAP lesions. Loose bodies were found and removed in 17 chronic and 4 acute cases (16.34% v 13.04%, P = .903). A partial-thickness articular rotator cuff tear was found in 14 patients: 12 with chronic dislocations and 2 with acute dislocations (11.53% v 8.69%, P = .694). The cuff tears were partial articular surface tears, involving less than 25% of the cuff thickness, and were treated with debridement, and cuff repair was not necessary in any case. The inverted pear configuration of the glenoid was found in 16 cases with chronic instability (15.38%), whereas no patient with an acutely dislocated shoulder had an inverted pear-shaped glenoid (P = .044). CONCLUSIONS: Associated, secondary intra-articular lesions are more frequent in patients with chronic compared with acute shoulder instability, probably as a result of the repeated dislocation or subluxation episodes. LEVEL OF EVIDENCE: Level IV, prognostic case series.

Distal radial and ulnar arteries perforator-based adipofascial flaps for covering hand traumatic defects.

AIM: The clinical value of adipofascial flaps based on distal ulnar or radial-artery perforators is demonstrated in a series of 14 patients with severe hand injuries and significant soft tissue defects requiring coverage. MATERIAL AND METHODS: There were 10 male and 4 female patients, aged between 23 and 72 years. The defects were 7 dorsal, 4 palmar, 1 combined dorsal-palmar, and 2 with thumb or total digit amputation. In the patients with a dorsal defect, the extensor tendons were intact in 2 cases, reconstructed in 2 cases, and reconstructed in 3 cases using silicon rods. Following debridement, a fascial flap based on a distal ulnar (12) or radial (4, 2 primarily and 2 secondarily) artery perforator was fashioned and used to cover the defect. A split thickness skin graft was used to cover the defect and the hand was immobilized for 2 weeks. RESULTS: All cases were followed up for at least 6 months. The donor and recipient sites healed uneventfully, and the functional result was very good in terms of wrist and hand joint range of motion, which approximated the normal rates. The extension or flexion deficit was less than 25 degrees. The esthetic result was satisfactory. Two ulnar flap partial (involving approximately 35% of the area) necroses have been treated using reversed radial-distal perforator flaps. CONCLUSION: The described fascial flaps offer several advantages over other local flaps, and are rather easy to perform and cover effectively both dorsal and palmar hand defects without causing significant functional deficits to the upper limb.