PubMed Health⌕ Search

Biomedical subjects

Anikar Chhabra

Publications and source records attributed to Anikar Chhabra.

15 recordsLinked to original sources
PubMed2006

Arthroscopic capsulolabral reconstruction for posterior instability of the shoulder: a prospective study of 100 shoulders.

BACKGROUND: There are few reports in the literature detailing arthroscopic treatment of unidirectional posterior shoulder instability. HYPOTHESIS: Arthroscopic capsulolabral reconstruction is effective in restoring stability and function and alleviating pain in athletes with symptomatic unidirectional posterior instability. This population has significant differences in glenoid and chondrolabral versions when compared with controls. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Ninety-one athletes (100 shoulders) with unidirectional recurrent posterior shoulder instability were treated with an arthroscopic posterior capsulolabral reconstruction and evaluated at a mean of 27 months postoperatively. A subset of 51 shoulders in contact athletes were compared with the entire group of 100 shoulders. Patients were evaluated prospectively with the American Shoulder and Elbow Surgeons scoring system. Stability, strength, and range of motion were evaluated preoperatively and postoperatively with standardized subjective scales. Forty-eight shoulders had magnetic resonance arthrograms performed and were available for review. The posterior inferior chondrolabral and bony glenoid versions were measured and compared with controls. RESULTS: At a mean of 27 months postoperatively, the mean American Shoulder and Elbow Surgeons score improved from 50.36 to 85.66 (P < .001). There were significant improvements in stability, pain, and function based on standardized subjective scales (P < .001). The contact athletes did not demonstrate any significant differences when compared with the entire cohort for any outcome measure. The results in the 71 shoulders followed for at least 2 years were similar to the overall group. On magnetic resonance arthrography, the shoulders with posterior instability were found to have significantly greater chondrolabral and osseous retroversion in comparison with controls (P < .001 and P = .008, respectively). CONCLUSION: Arthroscopic capsulolabral reconstruction is an effective, reliable treatment for symptomatic unidirectional recurrent posterior glenohumeral instability in an athletic population. Overall, 89% of patients were able to return to sport, with 67% of patients able to return to the same level postoperatively.

Adolescent↗
PubMed2006

Does irradiation affect the clinical outcome of patellar tendon allograft ACL reconstruction?

The clinical implications of using irradiation to sterilize allograft bone-patellar tendon-bone (BPTB) remains unknown. The purpose of this study was to compare the clinical outcome of anterior cruciate ligament (ACL) reconstruction with irradiated allograft versus autograft BPTB. We hypothesized that patients undergoing ACL reconstruction with irradiated BPTB allograft would have no significant differences in patient-reported and objective parameters compared to those undergoing autograft BPTB reconstruction. Patients who underwent ACL reconstruction with either irradiated allograft or autograft BPTB from 1996 to 2002 were eligible for this study. One hundred and two patients (39 allograft, 63 autograft) met the study criteria and were available for follow-up. The BPTB allografts were obtained from a single tissue bank and were sterilized with 2.5 Mrad of irradiation prior to distribution. Participants completed the International Knee Documentation Committee (IKDC) subjective knee form and returned for physical and radiographic examinations, instrumented measurement of laxity, and functional testing. Patients were evaluated at an average follow-up of 4.2 years (range 1.8-8.4). Those undergoing allograft reconstruction were older (44+/-8.4 vs. 25.3+/-9.3 years, p<0.001) and had a longer median time from injury to surgery (17.1 weeks vs. 9.7 weeks, p=0.04). There was no difference in IKDC Subjective Knee Scores between groups (86.7 allograft vs. 88.0 autograft, p=0.65). The average maximum manual KT-1000 side-to-side difference was 1.3 and 2.2 mm for allograft and autograft, respectively (p=0.04); however, after adjusting for age, this difference was no longer significant. 90.6% of the allograft and 82.8% of the autograft had normal/nearly normal overall IKDC physical examination rating (p=0.37). 66.7% of the allograft and 77.8% of the autograft returned to the same or more strenuous level of sports (p=0.25). Patients undergoing ACL reconstruction with irradiated allograft BPTB had similar clinical outcomes compared to those reconstructed with autograft BPTB. These data suggest that irradiation can be used to sterilize BPTB allograft without adversely affecting clinical outcome.

Activities of Daily Living↗
PubMed2006

Tunnel expansion after anterior cruciate ligament reconstruction with autogenous hamstrings: a comparison of the medial portal and transtibial techniques.

PURPOSE: The purpose of this study was to evaluate the effects of 2 techniques of drilling the femoral tunnel in anterior cruciate ligament (ACL) reconstruction (medial portal v transtibial) on tunnel expansion. METHODS: Autogenous hamstring ACL reconstructions performed by the senior author between July 1998 and July 2004, with a minimum 6-month radiographic follow-up, using the transtibial technique (41 patients) and the medial portal technique (34 patients), were evaluated. All procedures were performed via an endoscopic technique with identical postoperative rehabilitation and graft fixation. Lateral and 45 degrees posteroanterior (PA) radiographs were obtained for each patient at a minimum of 6 months postoperatively. The sclerotic margins of the femoral and tibial tunnels were measured at the widest dimension of the tunnel by 2 physicians and were compared with the initially drilled tunnel size after correction for radiographic magnification. Statistical analysis was performed to compare the 2 groups by use of the independent-samples t test, with significance set at .05. RESULTS: The mean percentage increase in the femoral tunnel was 38.20% +/- 17.76% for the medial portal technique and 53.96% +/- 21.72% for the transtibial technique on the PA view and 23.80% +/- 16.50% for the medial portal technique and 50.07% +/- 26.98% for the transtibial technique on the lateral view. This difference was statistically significant on both PA and lateral views. The mean percentage increase in the tibial tunnel was 31.81% +/- 14.39% for the medial portal technique and 36.31% +/- 17.81% for the transtibial technique on the PA view and 27.70% +/- 15.25% for the medial portal technique and 30.11% +/- 18.98% for the transtibial technique on the lateral view; however, these increases failed to reach statistical significance on either view. CONCLUSIONS: Femoral tunnel expansion for hamstring autologous ACL reconstructions is significantly lower for the medial portal technique when compared with the conventional transtibial technique. LEVEL OF EVIDENCE: Level III, retrospective, comparative therapeutic study.

Adolescent↗
PubMed2006

Single-bundle versus double-bundle posterior cruciate ligament reconstruction: scientific rationale and surgical technique.

Despite many recent advances in the understanding of the posterior cruciate ligament (PCL) and its function, the optimal treatment of PCL injuries remains controversial. Although it now is well known that the PCL is made up of two distinct bundles, each of which plays a vital role in achieving knee stability, questions abound regarding the need for double-bundle reconstruction rather than single-bundle techniques. Currently, the reconstruction technique is selected based on the injury pattern. In acute (< 3 weeks from the time of injury) combined PCL injuries (PCL/posterolateral corner, PCL/medial collateral ligament, and knee dislocations), a single-bundle reconstruction designed to replicate the anatomy of the anterolateral bundle is used. In acute or chronic PCL injuries in which both the posteromedial bundle of the PCL and the meniscofemoral ligaments remain intact, a single-bundle augmentation is used. A double-bundle reconstruction is performed when all three components of the PCL complex (anterolateral band, posteromedial band, and meniscofemoral ligaments) have been ruptured. These patterns are generally chronic, with severe knee laxity following a previous traumatic injury (PCL/posterolateral corner or knee dislocation). Tailoring the PCL reconstruction technique to the individual injury pattern will likely yield a reconstruction that better replicates the natural biomechanics of the native knee, thereby resulting in better functional outcomes.

Anterior Cruciate Ligament↗
PubMed2005

In vitro analysis of rotator cuff repairs: a comparison of arthroscopically inserted tacks or anchors with open transosseous repairs.

PURPOSE: The purpose of this study was to employ a cyclic loading protocol to compare rotator cuff repair strengths of arthroscopically inserted cuff tacks and suture anchors with the traditional open transosseous suture repair. TYPE OF STUDY: In vitro cadaveric analysis. METHODS: Full-thickness 1 x 3-cm rotator cuff defects were created in 25 fresh-frozen cadaveric shoulders, and were randomized to 1 of 4 repair groups: (1) open repair with transosseous sutures, (2) arthroscopic repair with 2 singly loaded suture anchors, (3) arthroscopic repair with 2 doubly loaded suture anchors, and (4) arthroscopic repair with cuff tacks. All repairs were cyclically loaded from 10 to 180 N, and the numbers of cycles to 50% (5-mm gap) and 100% (10-mm gap) failure were recorded. RESULTS: The number of cycles to 100% failure was significantly higher for the arthroscopic doubly loaded suture anchor repairs when compared with the (1) open transosseous suture repair (P = .009), (2) arthroscopic cuff tack repair (P = .003), and (3) arthroscopic singly loaded suture anchor repair (P = .02). Additionally, the number of cycles to 50% failure was significantly higher for all anchors versus open or tack repair (P = .03 for both). CONCLUSIONS: Immediate postoperative fixation of rotator cuff repairs with doubly loaded suture anchors was more stable than that provided by the open transosseous suture repairs, arthroscopic singly loaded suture anchors, or cuff tacks. However, additional evaluation is needed to examine the effects on the sustained strength of the repair throughout the healing process. CLINICAL RELEVANCE: These in vitro results indicate that superior immediate postoperative fixation of rotator cuff repairs may be achieved with the doubly loaded suture anchors. However, additional evaluation is needed to examine the effects on the sustained strength of the repair throughout the healing process.

Absorbable Implants↗
PubMed2005

The arthroscopic appearance of a normal anterior cruciate ligament in a posterior cruciate ligament-deficient knee: the posterolateral bundle (PLB) sign.

Partial anterior cruciate ligament (ACL) tears that result in functional instability are usually the result of a deficiency of the anteromedial bundle (AMB), and are evident arthroscopically by a prominent posterolateral bundle (PLB). As double-bundle ACL reconstructions are being suggested to recreate a more normal anatomy, the roles of each bundle are being more critically questioned. We present a case that describes the appearance of a normal ACL in a posterior cruciate ligament (PCL)-deficient knee in which the PLB of the ACL is prominent, giving the appearance of a complete tear of the AMB of the ACL, and scarring of this bundle to the PCL stump. On further inspection, and when the tibia was reduced, the normal appearance of the ACL returned, with visualization of the AMB obscuring the PLB. We have named this arthroscopic finding the "PLB sign." This finding confirms the individual roles of each bundle of the ACL. It is important to not misinterpret this abnormal appearance of the ACL as a partial ACL tear in a PCL-deficient knee.

Accidents, Traffic↗
PubMed2005

BMP-14 deficiency inhibits long bone fracture healing: a biochemical, histologic, and radiographic assessment.

OBJECTIVES: Bone morphogenetic proteins (BMPs) represent a distinct subset of the transforming growth factor-beta family best known for their role in joint formation and bone growth, and several recent clinical trials have begun to look at their efficacy in the augmentation of fracture healing. The goal of this research is to examine the effect of BMP-14, also known as growth differentiation factor-5 and cartilage- derived morphogenetic protein-1 (GDF-5, CDMP-1) on fracture healing by studying the long bone repair process in mice with a deficiency in this signaling peptide. METHODS: The animal model used for these studies was the BMP-14 (-/-) brachypodism (bp) mouse. Phenotypically normal heterozygous (+/-) littermates were used as controls. Closed mid shaft femur fractures were created and stabilized with intramedullary fixation in 8-week-old female mice. Forty-eight mice per genotype group were examined. On postoperative days 4, 7, 10, 14, 21, 28, 35, and 42, the mice were killed and the femurs and repair tissue were harvested for analysis. At each time point, the fracture sites were analyzed radiographically, histologically, and biochemically. For all quantitative analyses, the data were normalized and analyzed statistically using a 2-factor ANOVA test. RESULTS: Biochemically, peak values of normalized proteoglycan content were approximately 3 times less in the mutant fractures early in the time course of healing compared with the controls (P < 0.05). Histologically, BMP-14-deficient fractures exhibited a delay in peak area cell density, callus organization, and bone formation compared with controls. Radiographic analysis demonstrated that the peak callus was 2 weeks delayed and approximately 2 times less in the mutants compared with controls (P < 0.05). Radiographic grading of callus also demonstrated a significant difference after day 14. CONCLUSIONS: Based on histologic, radiographic, and biochemical analysis, BMP-14-deficient mice display a short-term delay in healing of approximately 1 to 2 weeks. The observed abnormalities seem to be the result of a delay in cellular recruitment and chondrocyte differentiation in the early stages fracture repair in the absence of BMP-14. These results support the hypothesis that BMP-14 deficiency leads to a delay in fracture healing. Further studies are warranted to more closely examine the role of BMP-14 in normal fracture healing and the mechanism by which it works.

Animals↗
PubMed2005

Surgical management of knee dislocations. Surgical technique.

BACKGROUND: The evaluation and management of knee dislocations remain variable and controversial. The purpose of this study was to describe our method of surgical treatment of knee dislocations with use of a standardized protocol and to report the clinical results. METHODS: Forty-seven consecutive patients presented with an occult (reduced) or grossly dislocated knee. Fourteen of these patients were not included in this series because of confounding variables: four had an open knee dislocation, five had vascular injury requiring repair, three were treated with external fixation, and two had associated injury. The remaining thirty-three patients underwent surgical treatment for the knee dislocation with our standard approach. Anatomical repair and/or replacement was performed with fresh-frozen allograft tissue. Thirty-one of the thirty-three patients returned for subjective and objective evaluation with use of four different knee-rating scales at a minimum of twenty-four months after the operation. RESULTS: Nineteen of the thirty-one patients were treated acutely (less than three weeks after the injury) and twelve, chronically. The mean Lysholm score was 91 points for the acutely reconstructed knees and 80 points for the chronically reconstructed knees. The Knee Outcome Survey Activities of Daily Living scores averaged 91 points for the acutely reconstructed knees and 84 points for the chronically reconstructed knees. The Knee Outcome Survey Sports Activity scores averaged 89 points for the acutely reconstructed knees and 69 points for the chronically reconstructed knees. According to the Meyers ratings, twenty-three patients had an excellent or good score and eight had a fair or poor score. Sixteen of the nineteen acutely reconstructed knees and seven of the twelve chronically reconstructed knees were given an excellent or good Meyers score. The average loss of extension was 1 degrees , and the average loss of flexion was 12 degrees . There was no difference in the range of motion between the acutely and chronically treated patients. Four acutely reconstructed knees required manipulation because of loss of flexion. Laxity tests demonstrated consistently improved stability in all patients, with more predictable results in the acutely treated patients. CONCLUSIONS: Surgical treatment of the knee dislocations in our series provided satisfactory subjective and objective outcomes at two to six years postoperatively. The patients who were treated acutely had higher subjective scores and better objective restoration of knee stability than did patients treated three weeks or more after the injury. Nearly all patients were able to perform daily activities with few problems. However, the ability of patients to return to high-demand sports and strenuous manual labor was less predictable.

Acute Disease↗
PubMed2005

Management of proximal femoral shaft fractures in osteopetrosis: a case series using internal fixation.

Osteopetrosis is a group of rare sclerosing bone dysplasias. Orthopedic concerns in osteopetrosis are principally related to the characteristic brittle "marble bone" in which fractures may be easily induced by relatively low-energy mechanisms. Femoral fractures are common in this patient population, and management presents a unique technical challenge. While osteopetrotic bone may be penetrated with a drill bit, the drill bit flutes are immediately filled with bone. This renders the drill ineffective, and generation of significant frictional heat can result in breakage of the drill. This case series describes the long-term management of nine osteopetrotic femoral fractures in three patients. The difficulties encountered in these cases prompted the development of a safe and efficacious technique for intramedullary fixation of these fractures.

Accidental Falls↗
PubMed2004

Recreating an acceptable angle of the tibial tunnel in the coronal plane in anterior cruciate ligament reconstruction using external landmarks.

Although it is still unclear what the ideal angle of the tibial tunnel in the coronal plane should be when performing anterior cruciate ligament (ACL) reconstruction using the endoscopic single-incision technique, researchers have recently shown that erroneous placement of the tibial tunnel in the coronal plane can lead to graft laxity and loss of extension. We have developed a simple, reproducible technique to provide an acceptable angle of the tibial tunnel in the coronal plane when using the endoscopic single-incision ACL reconstruction technique by using bony landmarks. With the ACL guide parallel to the femur, the external portion of the tibial tunnel guide is rotated so that the guidewire starting point is made at the bisection of a line between the tibial tubercle and the posteromedial border of the tibia. We have confirmed this technique in cadaver studies with angles of the tibial tunnel less than 75 degrees in the coronal plane in all cases. In addition, we have used this technique with good clinical results in over 100 ACL reconstructions.

Anterior Cruciate Ligament↗
PubMed2004

Arthroscopic repair of a posterior humeral avulsion of the inferior glenohumeral ligament (HAGL) lesion.

Recently, the humeral avulsion of the inferior glenohumeral ligament (HAGL) has been described as a cause of shoulder instability. All documented cases in the literature describe the avulsion as an anterior and lateral disruption leading to anterior instability. We detail a previously unreported case of a HAGL lesion involving the posterior band of the inferior glenohumeral ligament. Arthroscopic reattachment using an additional posteroinferior portal resulted in a successful repair.

Adolescent↗
PubMed2003

Osteochondral autograft plug transfer: achieving perpendicularity.

Although osteochondral autograft plug transfer is a common clinical procedure, few authors have addressed the outcomes or how variations and surgical technique can influence results. Variations in arthroscopic versus open harvesting techniques, as well as intercondylar notch versus lateral trochlear ridge harvest locations, influence the ability to obtain the most perpendicular osteochondral grafts. Eight fresh-frozen cadaveric knees were studied. Four plugs were harvested from each knee, two from the superior lateral intercondylar notch area and two from the superior lateral trochlear ridge area. Plugs harvested from the lateral trochlear ridge (86.9 degrees) were statistically more perpendicular than the plugs harvested from the intercondylar notch (83.3 degrees) (P=.02). No statistically significant difference was noted between the open (86.4 degrees) and arthroscopic (83.8 degrees) harvesting techniques (P=.11).

Aged↗
PubMed2003

Meniscal repair with the Rapid Loc device: a cadaveric study.

The devices available for all-inside meniscal repair were evaluated using a cadaver model. Rapid Loc devices (Mitek, Westwood, Mass) were inserted arthroscopically into 8 fresh-frozen cadaveric knees (age range: 66-78 years) in the posterior regions of the menisci at 5- to 7-mm intervals. Forty-eight devices were placed (3 in each meniscus), and the knees were subsequently dissected to determine the location of the inserted devices. Devices were correctly inserted in 40 (833%) of 48 knees. No problems were noted with loss of fixation on the periphery of the meniscus. Entrapment of the popliteus tendon (3 of 8) and superficial medial collateral ligament (2 of 16) were the only major problems with the device.

Aged↗
PubMed2003

Ultrastructural determinants of murine achilles tendon strength during healing.

The mechanisms by which tendon strength is established during growth and development and restored following injury are not completely understood and are likely to be complex, multifactorial processes. Several studies examining the relationship between mechanical behavior and ultrastructural characteristics of tendons and ligaments during growth and maturation suggest that collagen fibril diameter is strongly correlated with tendon strength. Because of the similarities between development and repair processes of musculoskeletal tissues, increases in tendon strength during healing may be related to increases in fibril ultrastructural parameters such as fibril size, numerical density, and area fraction. In this study, we compared murine Achilles tendons at various time points after tenotomy with sham-operated controls in tensile tests to failure and examined tendons using electron microscopy to assess collagen fibril ultrastructure. We found that in the 6-week period following Achilles tenotomy, fibril mean diameter remained significantly smaller than sham-side diameter by a factor of 2-3. Despite the persistently small fibril size, increasing numerical density resulted in a gradual increase in fibril area fraction. Biomechanical strength did not reach that of intact tendons until some time between 5 and 7 weeks, approximately the same time period when fibril area fraction began to approach sham values. These data suggest that parameters other than collagen fibril size are most responsible for increased tendon strength during healing.

Achilles Tendon↗