Ivan Wong

Graft Utilization in the Augmentation of Large-to-Massive Rotator Cuff Repairs A Systematic Review

Background: Current treatment options for symptomatic large-to-massive rotator cuff tears can reduce pain, but failure rates remain high. Surgeons have incorporated synthetic and biologic grafts to augment these repairs, with promising results. Multiple reviews exist that summarize these products; however, no systematic review has investigated the grafts’ ability to maintain structural integrity after augmentation of large-to-massive rotator cuff repairs. Purpose: To systematically review and evaluate the effectiveness of grafts in the augmentation of large-to-massive rotator cuff repairs. Study Design: Systematic review. Methods: A comprehensive search of 4 reputable databases was completed. Inclusion criteria were (1) large-to-massive rotator cuff tear, (2) graft augmentation of primary repairs ± primary repair control group, and (3) minimum clinical and radiologic follow-up of 12 months. Two reviewers screened the titles, abstracts, and full articles and extracted the data from eligible studies. Results were summarized into evidence tables stratified by graft origin and level of evidence. Results: Ten studies fit the inclusion criteria. Allograft augmentation was functionally and structurally superior to primary repair controls, with intact repairs in 85% versus 40% of patients (P < .01). This was supported by observational study data. Xenograft augmentation failed to demonstrate superiority to primary repair controls, with worse structural healing rates (27% vs 60%; P =.11). Both comparative studies supported this finding. There have also been many reports of inflammatory reactions with xenograft use. Polypropylene patches are associated with improved structural (83% vs 59% and 49%; P < .01) and functional outcomes when compared with controls and xenograft augmentation; however, randomized data are lacking. Conclusion: Augmentation of large-to-massive rotator cuff repairs with human dermal allografts is associated with superior functional and structural outcome when compared with conventional primary repair. Xenograft augmentation failed to demonstrate a statistically significant difference and may be associated with worse rerupture rates and occasional severe inflammatory reactions. Polypropylene patches have initial promising results. Research in this field is limited; future researchers should continue to develop prospective, randomized controlled trials to establish clear recommendations.

Knee joint motion and muscle activation patterns are altered during gait in individuals with moderate hip osteoarthritis compared to asymptomatic cohort

BACKGROUND Knee replacements are common after hip replacement for end stage osteoarthritis. Whether abnormal knee mechanics exist in moderate hip osteoarthritis remains undetermined and has implications for understanding early osteoarthritis joint mechanics. The purpose of this study was to determine whether three-dimensional (3D) knee motion and muscle activation patterns in individuals with moderate hip osteoarthritis differ from an asymptomatic cohort and whether these features differ between contra- and ipsilateral knees. METHODS 3D motions and medial and lateral quadriceps and hamstring surface electromyography were recorded on 20 asymptomatic individuals and 20 individuals with moderate hip osteoarthritis during treadmill walking, using standardized collection and processing procedures. Principal component analysis was used to derive electromyographic amplitude and temporal waveform features. 3D stance-phase range of motion was calculated. A 2-factor repeated analysis of variance determined significant within-group leg and muscle differences. Students t-tests identified between group differences, with Bonferroni corrections where applicable (α=0.05). FINDINGS Lower sagittal plane motion between early and mid/late stance (5°, P=0.004, effect size: 0.96) and greater mid-stance quadriceps activity was found in the osteoarthritis group (P=0.01). Compared to the ipsilateral knee, a borderline significant increase in mid-stance hamstring activity was found in the contra-lateral knee of the hip osteoarthritis group (P=0.018). INTERPRETATION Bilateral knee mechanics were altered, suggesting potentially increased loads and knee muscle fatigue. There was no indication that one knee is more susceptible to osteoarthritis than the other, thus clinicians should include bilateral knee analysis when treating patients with hip osteoarthritis.

Graft Utilization in the Bridging Reconstruction of Irreparable Rotator Cuff Tears: A Systematic Review

Background: Rotator cuff tears are one of the most common conditions affecting the shoulder. Because of the difficulty in managing massive rotator cuff tears and the inability of standard techniques to prevent arthropathy, surgeons have developed several novel techniques to improve outcomes and ideally alter the natural history. Purpose: To systematically review the existing literature and analyze reported outcomes to evaluate the effectiveness of using a bridging graft reconstruction technique to treat large to massive irreparable rotator cuff tears. Study Design: Systematic review. Methods: A systematic search of PubMed, EMBASE, CINAHL, and CENTRAL was employed with the key terms “tear,” “allograft,” and “rotator cuff.” Eligibility was determined by a 3-phase screening process according to the outlined inclusion/exclusion criteria. Data in relation to the primary and secondary outcomes were summarized. The results were synthesized according to the origin of the graft and the level of evidence. Results: Fifteen studies in total were included in this review: 2 comparative studies and 13 observational case series. Both the biceps tendon and the fascia lata autograft groups had significantly superior structural integrity rates on magnetic resonance imaging at 12-month minimum follow-up when compared with their partial primary repair counterparts (58% vs 26%, P = .036; 79% vs 58%, P < .05), respectively. Multiple noncomparative case series investigating allografts, xenografts, and synthetic materials for bridging reconstruction of large to massive rotator cuff tears demonstrated high structural healing rates (74%-90%, 73%-100%, and 60%-90%, respectively). Additionally, both comparative studies and case series demonstrated a general improvement of patients’ functional outcome scores. Conclusion: Using a graft for an anatomic bridging rotator cuff repair results in improved function on objective testing and may be functionally better than nonanatomic or partial repair of large to massive rotator cuff tears. Allograft or xenograft techniques appear to be favorable options, given demonstrated functional improvement, imaging-supported graft survival, and lack of harvest complication risk. More high-quality randomized controlled studies are needed to further assess this technique.

Hip joint motion and gluteal muscle activation differences between healthy controls and those with varying degrees of hip osteoarthritis during walking

PURPOSE Compare gluteal muscle activation patterns and three-dimensional hip joint movements among those with severe hip osteoarthritis (OA), moderate OA and a healthy group during walking. SCOPE 20 individuals with severe OA, 20 with moderate OA and 20 healthy individuals were recruited. Three-dimensional hip motion and surface electromyograms from gluteus maximus and medius were collected during treadmill walking at a self-selected speed. Angular displacement characteristics were calculated for three-dimensional hip motions. Principal component analysis extracted amplitude and temporal features from electromyographic waveforms. Analysis of Variance models and student t-tests using Bonferroni corrections determined between group differences in these gait features (α = 0.05). CONCLUSIONS Sagittal plane hip range of motion was significantly reduced with increasing severity of OA (p < 0.05) where as frontal and transverse plane range of motion was reduced in the severe OA group only (p < 0.05). Activation patterns of gluteus medius and maximus did not differ between the healthy group and those with moderate hip OA (p > 0.05). Individuals with severe OA walking with more prolonged gluteus maximus activation and prolonged and less dynamic gluteus medius activation compared to the other two groups (p < 0.05). This study highlights the changing function of the hip joint during walking with increasing hip OA severity.

Arthroscopic Bullet Removal from the Acetabulum (Hip Joint)

Hip arthroscopy has been shown to offer minimally invasive access to the hip joint compared with standard open arthrotomy. The use of arthroscopy for diagnosing and treating disorders about the hip continues to evolve. This study describes a case that involves arthroscopic removal of a bullet from a low-velocity gunshot wound. The patient sustained a gunshot wound that entered the abdomen and traversed the small bowel, sigmoid colon then penetrated the urinary bladder before ending up in the medial wall of the acetabulum. After surgical repair of the viscus, the bullet was retrieved from the hip joint using standard arthroscopic portals and a fracture table. A number of issues led to the decision to use arthroscopy. Most importantly was the need to minimize soft tissue dissection, which was required to access the bullet, without interfering with previous wound at the suprapubic area. The risks of potential bullet fragmentation and migration, as well as a possible abdominal compartment syndrome were considered before proceeding. Arthroscopy allowed adequate inspection of the articular surface, irrigation of the joint, and removal of the foreign body while avoiding an invasive arthrotomy with its associated morbidity and soft tissue disruption. This surgical technique afforded a very satisfactory outcome for this patient and serves as a model for others when encountering a similar injury pattern in a trauma patient. It is a procedure that can be performed safely, quickly, and with minimal complications for surgeons with experience in arthroscopy of the hip joint.

Radiographic Diagnosis of Pincer-Type Femoroacetabular Impingement: A Systematic Review:

Background: Femoroacetabular impingement (FAI) is a well-recognized condition that causes hip pain and can lead to early osteoarthritis if not managed properly. With the increasing awareness and efficacy of operative treatments for pincer-type FAI, there is a need for consensus on the standardized radiographic diagnosis. Purpose: To perform a systematic review of the evidence regarding imaging modalities and radiographic signs for diagnosing pincer-type FAI. Study Design: Systematic review; Level of evidence, 4. Methods: A literature review was performed in 2016 using the Cochrane, PubMed, and Embase search engines. All articles focusing on a radiographic diagnosis of pincer-type FAI were reviewed. Each of the included 44 articles was assigned the appropriate level of evidence, and the particular radiographic marker and/or type of imaging were also summarized. Results: There were 44 studies included in the final review. Most of the articles were level 4 evidence (26 articles), and there were 12 level 3 and 6 level 2 articles. The crossover sign was the most commonly used radiographic sign (27/44) followed by the lateral center-edge angle (22/44). Anteroposterior (AP) pelvis plain radiographs were the most commonly used imaging modality (33 studies). Poor-quality evidence exists in support of most currently used radiographic markers, including the crossover sign, lateral center-edge angle, posterior wall sign, ischial spine sign, coxa profunda, acetabular protrusion, and acetabular index. There is poor-quality conflicting evidence regarding the use of the herniation pit to diagnose pincer-type FAI. Some novel measurements, such as β-angle, acetabular roof ratio, and acetabular retroversion index, have been proposed, but they also lack support from the literature. Conclusion: No strong evidence exists to support a single best set of current radiographic markers for the diagnosis of pincer-type FAI, largely due to the lack of better quality trials (levels 1 and 2) that compare conventional radiographic findings with the gold standard, which is the intraoperative findings. More sophisticated imaging modalities such as computed tomography and magnetic resonance arthrography are often needed to diagnose pincer-type FAI, and these investigations are relatively accurate in assessing labral pathology or cartilage damage.

The effect of age and knee osteoarthritis on muscle activation patterns and knee joint biomechanics during dual belt treadmill gait

PURPOSE To compare a group of individuals with moderate medial compartment knee osteoarthritis (OA) to both an age-matched asymptomatic group of older adults and younger adults to determine whether differences in knee joint muscle activation patterns and joint biomechanics exist during gait between these three groups. SCOPE 20 young adults, 20 older adults, and 40 individuals with moderate knee OA were recruited. Using standardized procedures, surface electromyograms were recorded from the vastus lateralis and medialis, rectus femoris and the medial and lateral hamstrings. All individuals walked on a dual belt instrumented treadmill while segment motions and ground reaction forces were recorded. Sagittal plane motion and net external sagittal and frontal plane moments were calculated. Discrete measures and principal component analyses extracted amplitude and temporal waveform features. Analysis of Variance models using Bonferroni corrections determined between and within group differences in these gait features (α=0.05). CONCLUSIONS Individuals with knee OA have distinct biomechanics and muscle activation patterns when compared to age-matched asymptomatic adults and younger adults whereas differences between the young and older adults were few and included only measures of muscle activation amplitude.

Arthroscopic Treatment of Shoulder Instability With Glenoid Bone Loss Using Distal Tibial Allograft Augmentation: Safety Profile and Short-Term Radiological Outcomes

Background: The results of arthroscopic anterior labral repair have demonstrated high failure rates in patients with significant glenoid bone loss. Several reconstruction procedures using a bone graft have been developed to overcome bone loss. Purpose: The primary objective of this study was to generate a safety profile for arthroscopic anatomic glenoid reconstruction using a distal tibial allograft. The secondary objective was to evaluate the radiological outcomes of patients who underwent this procedure. Study Design: Case series; Level of evidence, 4. Methods: This retrospective review included the medical charts and diagnostic images of 42 consecutive patients who underwent arthroscopic shoulder stabilization by means of capsule-labral reattachment and bony augmentation with a distal tibial allograft. The safety profile was measured by detecting intraoperative or postoperative complications, including neurovascular (nerves and blood vessels) injuries, bleeding, infections, and dislocations. A radiological evaluation was conducted by assessing computed tomography (CT) scans obtained preoperatively and at approximately 6 months postoperatively. Results: A total of 42 patients (29 male, 13 female) with a mean age of 26.73 ± 9.01 years were included. An excellent safety profile was observed, with no intraoperative complications, neurovascular injuries, adverse events, bleeding, or infections. CT bone scans were obtained for 31 patients, and the mean follow-up for CT scanning (to measure resorption and union) was 6.31 ± 1.20 months (range, 6-7.5 months). There were no cases of nonunion or partial union. Thirteen patients (42%) had no resorption, whereas 13 (42%) and 5 (16%) patents had <50% and ≥50% resorption, respectively. Conclusion: Arthroscopic shoulder stabilization with distal tibial allograft reconstruction is a safe operative procedure with a minimal risk to neurovascular structures. Most patients had a healed allograft, but 16% of patients had ≥50% resorption on CT at 6 months. Studies with a longer follow-up are recommended for better assessment of the safety profile.

Passive hip movement measurements related to dynamic motion during gait in hip osteoarthritis

Reduced sagittal plane range of motion (ROM) has been reported in individuals with hip osteoarthritis (OA) both during walking and passive testing. The purpose of this study was to determine if a relationship exists between hip extension ROM recorded during gait and passive hip extension ROM in individuals with moderate and severe hip OA, in comparison to an asymptomatic group. Sagittal plane hip ROM was calculated using skin surface marker trajectories captured during treadmill walking at self‐selected speed. Passive hip ROM was measured using standardized position and recording procedures with a goniometer. Sagittal plane extension, flexion, and overall ROM were measured dynamically and passively. A two‐way mixed model analysis of variance determined significant differences between groups and between passive and dynamic ROM (α = 0.05). Pearson correlations determined relationships between passive and dynamic ROM. Significant group by ROM interactions were found for flexion and extension ROM (p < 0.05). For extension, the severe OA group had less dynamic and passive ROM compared to the other groups and greater passive than dynamic ROM (p < 0.05). For flexion, significant differences in passive ROM existed between all three groups (p < 0.05) whereas no differences were found for dynamic flexion (p < 0.05). Significant correlations between dynamic and passive hip extension were found in the moderate (r = 0.596) and severe OA (r = 0.586) groups, and no correlation was found in the asymptomatic group (r = 0.139). Passive ROM explains variance in dynamic ROM measurements obtained during gait in individuals with moderate and severe hip OA which have implications for the design of treatment strategies targeting walking pathomechanics.

Dual-belt treadmill familiarization: Implications for knee function in moderate knee osteoarthritis compared to asymptomatic controls

Background: Effect of treadmill familiarization on knee function in osteoarthritis is not clear. Purpose was to determine whether spatiotemporal characteristics, knee joint biomechanics and muscle activation patterns change as individuals with and without medial compartment knee osteoarthritis familiarize to dual‐belt treadmill walking over 6 min. Methods: 20 individuals with knee osteoarthritis and 20 asymptomatic controls walked at a self‐selected speed. Spatiotemporal characteristics, sagittal plane joint motions, sagittal and frontal plane moments and knee joint muscle activation patterns, amplitude normalized to maximum isometric contractions were analyzed. Discrete measures were extracted from each biomechanical waveform and principal component analysis was used to determine knee joint muscle activation patterns. Statistical significance was determined using Analysis of Variance models (alpha = 0.05). Findings: Spatiotemporal gait characteristics, knee motion and moment differences were found between groups however no group by time interactions existed and no changes in these variables were found over 6 min of walking. Group differences in muscle activation patterns were found in all muscle activations. Muscle activation amplitude and patterns at minute 5 and 6 were generally lower, less prolonged and more dynamic when compared to minute 1 and 3. Interpretation: Individuals with and without medial compartment knee osteoarthritis familiarized to treadmill walking in a similar manner. Minimal changes to knee biomechanics were found during treadmill familiarization. Five to six minutes of familiarization should be considered for surface electromyography in these populations. HighlightsDual belt treadmill familiarization in knee osteoarthritis and asymptomatic controlsGroup effects not affected by treadmill familiarizationNo change in spatiotemporal and gait biomechanics over 6 min of walkingMuscle activation amplitudes and patterns affected by treadmill familiarizationAt least 5 min of dual belt treadmill walking familiarization is recommended.