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Dive into the research topics where Christopher B. Dewing is active.

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Featured researches published by Christopher B. Dewing.


American Journal of Sports Medicine | 2007

Arthroscopic Stabilization in Patients With an Inverted Pear Glenoid: Results in Patients With Bone Loss of the Anterior Glenoid

Timothy S. Mologne; Matthew T. Provencher; Kyle A. Menzel; Tyler Vachon; Christopher B. Dewing

Background Recent literature has demonstrated that the success rates of arthroscopic stabilization of glenohumeral instability deteriorate in patients with an anteroinferior glenoid bone deficiency, also known as the “inverted pear” glenoid. Purpose This study was conducted to assess the outcomes of arthroscopic stabilization for recurrent anterior shoulder instability in patients with a mean anteroinferior glenoid bone deficiency of 25% (range, 20%-30%). Study Design Cohort study; Level of evidence, 3. Methods Twenty-one of 23 patients (91% follow-up) undergoing arthroscopic stabilization surgery and noted to have a bony deficiency of the anteroinferior glenoid of 20% to 30% were reviewed at a mean follow-up of 34 months (range, 26-47). The mean age was 25 years (range, 20-34); 2 patients were female and 19 were male. All patients were treated with a primary anterior arthroscopic stabilization using a mean of 3.2 suture anchors (range, 3-4). Eleven patients had a bony Bankart that was incorporated into the repair; 10 had no bone fragment and were considered attritional bone loss. Outcomes were assessed using the Rowe score, the American Shoulder and Elbow Surgeons (ASES) Score, the Single Assessment Numeric Evaluation (SANE), and the Western Ontario Shoulder Instability (WOSI) Index. Findings of recurrent instability and dislocation events were documented. Results Two patients (9.5%) experienced symptoms of recurrent subluxation, and 1 (4.8%) sustained a recurrent dislocation that required revision open surgery. The mean postoperative outcomes scores were as follows SANE = 88.1 (range, 65-100; standard deviation [SD] 9.0); Rowe = 85.2 (range, 55-100; SD 14.1); ASES Score = 93.1 (range, 78-100; SD 5.3); and WOSI Index = 398 (82% of normal; range, 30-1175; SD 264). No patient with a bony fragment experienced a recurrent subluxation or dislocation, and mean outcomes scores for patients with a bony fragment were better than those with no bony fragment (P = .08). No patient required medical discharge from the military for his or her shoulder condition. Conclusions Arthroscopic stabilization for recurrent instability, even in the presence of a significant bony defect of the glenoid, can yield a stable shoulder; however, outcomes are not as predictable especially in attritional bone loss cases. Longer-term follow-up is needed to see if these results hold up over time.


Arthroscopy | 2010

Arthroscopic labral reconstruction in the hip using iliotibial band autograft: technique and early outcomes.

Marc J. Philippon; Karen K. Briggs; Connor J. Hay; David A. Kuppersmith; Christopher B. Dewing; Michael J. Huang

PURPOSE The purpose of this study was to investigate the indications for and outcomes of arthroscopic labral reconstruction in the hip by use of iliotibial band (ITB) autograft. METHODS Between August 2005 and May 2008, the senior author (M.J.P.) performed 95 arthroscopic labral reconstructions using an ITB autograft in patients with advanced labral degeneration or deficiency. There were 47 patients who had undergone surgery at a minimum of 1 year previously and met the inclusion criteria. The modified Harris Hip Score (MHHS) and patient satisfaction were used to measure outcomes postoperatively. The labral autograft was harvested from the ITB through a separate incision. The graft was sutured to the intact labral remnant in the region of labral deficiency, re-establishing the suction seal of the hip joint. RESULTS There were 32 men and 15 women. The mean age at the time of surgery was 37 years (range, 18 to 55 years). The mean time from the onset of symptoms to labral reconstruction was 36 months (range, 1 month to 12 years). Subsequent total hip arthroplasty was performed in 4 patients (9%). Follow-up was obtained in 37 of the remaining 43 patients. The mean time to follow-up was 18 months (range, 12 to 32 months). The mean MHHS improved from 62 (range, 35 to 92) preoperatively to 85 (range, 53 to 100) postoperatively (P = .001). Median patient satisfaction was 8 out of 10 (range, 1 to 10). Patients who were treated within 1 year of injury had higher MHHSs than patients who waited longer than 1 year (93 v 81, P = .03). The independent predictor of patient satisfaction with outcome after labral reconstruction was age. CONCLUSIONS This study showed that patients who have labral deficiency or advanced labral degeneration had good outcomes and high patient satisfaction after arthroscopic intervention with acetabular labral reconstruction. Lower satisfaction was associated with joint space narrowing and increased age. Patients who waited longer than 1 year from the time of injury to surgery had lower function at follow-up than those treated in the first year. LEVEL OF EVIDENCE Level IV, therapeutic case series.


Journal of Shoulder and Elbow Surgery | 2009

Treatment of osseous defects associated with anterior shoulder instability.

Joseph R. Lynch; Jeremiah Clinton; Christopher B. Dewing; Winston J. Warme; Frederick A. Matsen

Bone loss of the glenoid and/or humerus is a common consequence of traumatic anterior shoulder instability and can be a cause of recurrent instability after a Bankart repair. Accurate characterization of the size and location of osseous defects associated with traumatic instability is important when planning treatment. Open or arthroscopic soft tissue repairs are usually sufficient when less than 25% of the width of the glenoid bone has been lost. Bone replacement techniques may be necessary when glenoid bone loss is greater than 25% of the glenoid width. Glenoid bone restoration techniques include the use of a tricortical iliac crest graft or the transfer of the coracoid process to the area of glenoid deficiency. Bone grafting becomes a strong consideration when soft tissue repairs have failed to restore stability. Treatment of these severe defects may be followed by osteoarthritis. The destabilizing effects of anterior glenoid bone defects are compounded by concurrent defects of the posterior-lateral humeral head, commonly known as Hill-Sachs lesions, which can engage the glenoid defect. Large humeral head defects can be treated by transhumeral bone grafting techniques or osteoarticular allograft reconstruction. Prosthetic replacement of the proximal humerus is considered for humeral head defects involving more than 40% of the articular surface. Understanding the importance of humeral and glenoid bone deficiencies may help guide the treatment of recurrent anterior glenohumeral instability.


Arthroscopy | 2011

Anatomy, Function, Injuries, and Treatment of the Long Head of the Biceps Brachii Tendon

Florian Elser; Sepp Braun; Christopher B. Dewing; J. Erik Giphart; Peter J. Millett

Lesions of the long head biceps tendon (LHB) are frequent causes of shoulder pain and disability. Biceps tenotomy and tenodesis have gained widespread acceptance as effective procedures to manage both isolated LHB pathology and combined lesions of the rotator cuff and biceps-labral complex. The function of the LHB tendon and its role in glenohumeral kinematics presently remain only partially understood because of the difficulty of cadaveric and in vivo biomechanical studies. The purpose of this article is to offer an up-to-date review of the anatomy and biomechanical properties of the LHB and to provide an evidence-based approach to current treatment strategies for LHB disorders.


Spine | 2008

The outcomes of lumbar microdiscectomy in a young, active population: correlation by herniation type and level.

Christopher B. Dewing; Matthew T. Provencher; Robert H. Riffenburgh; Stewart Kerr; Richard E. Manos

Study Design. Prospective longitudinal clinical study. Objective. The purpose of our article was to investigate the clinical outcomes with type and level of disc herniation in a young, active population undergoing lumbar microdiscectomy. Summary of Background Data. There are few reported outcomes studies on the relationship between disc herniation level, type of disc herniation, and surgical outcomes of lumbar microdiscectomy in a young, active population. Methods. One hundred ninety-seven (197) consecutive single-level lumbar microdiscectomies performed by a single surgeon were prospectively followed over a 3-year period. All patients had failed a period of nonoperative care including physical therapy and/or transforaminal epidural steroid injections. One hundred eighty-three patients (139 males, 44 females) with a mean age of 27.0 years (range 19–46 years) were prospectively followed for a mean of 26 months (range, 12–38 months). Outcomes were assessed using Visual Analog Scale (VAS), Oswestry disability index, patient satisfaction, return to military duty, and need for additional surgery. The type of disc herniation (contained, extruded, or sequestered) and the lumbar level of herniation were also recorded. Results. At final follow-up, 84% (154 of 183) of patients had returned to unrestricted military duty; 16% (29) had been medically discharged. The mean decrease in VAS leg pain score was 4.7 points (from mean preoperative 7.2 to mean postoperative 2.5); 80% (146) reported a decrease of greater than 2 points. The mean Oswestry index improved from 53.6 before surgery to 21.2 at final follow-up. Overall, 85% (156) were satisfied with their surgery. Six patients had recurrent herniations (3%) with 4 of the 6 undergoing additional surgery. Patients with preoperative VAS scores consistent with a preponderance of radicular leg pain versus back pain demonstrated better surgical outcomes in all categories (P < 0.001) When classified by disc herniation type, sequestered discs at all levels demonstrated better Oswestry and VAS scores versus extruded or contained disc herniations. (P < 0.001) Disc herniations at the L5–S1 level had significantly greater improvements in both mean VAS leg and Oswestry outcome scores than disc herniations at the L4–L5 level. (P < 0.001) Preexisting restricted duty status at time of first surgical consultation was associated with poorer outcomes. Smokers had a significantly lower return to full active military duty (P = 0.037). Conclusion. Microdiscectomy for symptomatic lumbar disc herniations in young, active patients with a preponderance of leg pain who have failed nonoperative treatment demonstrated a high success rate based on validated outcome measures, patient satisfaction, and return to active duty. Patients with disc herniations at the L5–S1 level had significantly better outcomes than did those at the L4–L5 level. Patients with sequestered or extruded lumbar disc herniations had significantly better outcomes than did those contained herniations. Patients with contained disc herniations, a predominance of back pain, on restricted duty and smoking should be counseled before surgery of the potential for less satisfaction, poorer outcomes scores, and decreased return to duty rates.


American Journal of Sports Medicine | 2013

A Prospective Analysis of 179 Type 2 Superior Labrum Anterior and Posterior Repairs Outcomes and Factors Associated With Success and Failure

Matthew T. Provencher; Frank McCormick; Christopher B. Dewing; Sean McIntire; Daniel J. Solomon

Background: There is a paucity of type 2 superior labrum anterior and posterior (SLAP) surgical outcomes with prospective data. Purpose: To prospectively analyze the clinical outcomes of the arthroscopic treatment of type 2 SLAP tears in a young, active patient population, and to determine factors associated with treatment success and failure. Study Design: Case-control study; Level of evidence, 3. Methods: Over a 4-year period, 225 patients with a type 2 SLAP tear were prospectively enrolled. Two sports/shoulder-fellowship-trained orthopaedic surgeons performed repairs with suture anchors and a vertical suture construct. Patients were excluded if they underwent any additional repairs, including rotator cuff repair, labrum repair outside of the SLAP region, biceps tenodesis or tenotomy, or distal clavicle excision. Dependent variables were preoperative and postoperative assessments with the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and Western Ontario Shoulder Instability (WOSI) scores and independent physical examinations. A failure analysis was conducted to determine factors associated with failure: age, mechanism of injury, preoperative outcome scores, and smoking. Failure was defined as revision surgery, mean ASES score below 70, or an inability to return to sports and work duties, which was assessed statistically with the Student t test and stepwise logarithmic regression. Results: There were 179 of 225 patients who completed the follow-up for the study (80%) at a mean of 40.4 months (range, 26-62 months). The mean preoperative scores (WOSI, 54%; SANE, 50%; ASES, 65) improved postoperatively (WOSI, 82%; SANE, 85%; ASES, 88) (P < .01). The mean postoperative range of motion was 159° of flexion, 151° of abduction, and 51° of external rotation at the side, which was less than the mean preoperative range of motion (164° of flexion, 166° of abduction, and 56° of external rotation at the side). Of the 179 patients, 66 patients (36.8%) met failure criteria. Fifty patients elected revision surgery. Advanced age within the cohort (>36 years) was the only factor associated with a statistically significant increase in the incidence of failure. Those who were deemed failed had a mean age of 39.2 years (range, 29-45 years) versus those who were deemed healed with a mean age of 29.7 years (range, 18-36 years) (P < .001). The relative risk for failure for patients older than 36 years was 3.45 (95% CI, 2.0-4.9). Conclusion: Arthroscopic SLAP repair provides a clinical and statistically significant improvement in shoulder outcomes. However, a reliable return to the previous activity level is limited; 37% of patients had failure, with a 28% revision rate. Age greater than 36 years was associated with a higher chance of failure. Additional work is necessary to determine the optimal diagnosis, indications, and surgical management for those with SLAP injuries.


American Journal of Sports Medicine | 2008

An Analysis of Capsular Area in Patients with Anterior, Posterior, and Multidirectional Shoulder Instability

Christopher B. Dewing; Frank McCormick; S. Josh Bell; Daniel J. Solomon; Mark Stanley; Timothy B. Rooney; Matthew T. Provencher

Background Although increased capsular volume has been implicated in shoulder instability, there is a paucity of clinical evidence to quantify the size of the capsule with specific instability conditions of the shoulder. Hypothesis Shoulder capsular area, as measured by magnetic resonance arthrography, is increased with specific patterns of shoulder instability. Study Design Cross-sectional study; Level of evidence, 4. Methods During an 8-month period, all patients with a diagnosis of anterior (n = 19), posterior (n = 14), or multidirectional (n = 13) instability of the shoulder and who were assessed with a magnetic resonance arthrogram were reviewed. A group of 10 control patients without clinical instability were also identified. The magnetic resonance arthrograms of all groups were randomly mixed, and 5 reviewers recorded measures of capsular length and area and determined labral abnormalities. The magnetic resonance arthrogram measurements were compared between groups, and interobserver agreement was determined. Results The cross-sectional area of the capsule was increased in patients with posterior (P = .017) or multidirectional instability (P = .021) versus controls, but not in patients with anterior instability. Additionally, the posteroinferior cross-sectional area was increased in patients with posterior (P = .001), multidirectional (P = .003), and anterior (P = .008) instability. In patients with a posterior labral tear, the mean axial (P = .043) and mean posteroinferior sagittal cross-sectional area (P = .011) was increased, but there were no differences in cross-sectional area for those with an anterior labral tear. The overall interobserver reliability was very good (correlation coefficient range, 0.68–0.94). Conclusion Our results reinforce the concept that capsular elongation and laxity, either preexisting or acquired, play a role in certain instability conditions of the shoulder. Additional work is needed to determine how to correlate surgical decision making with the cross-sectional area measurements demonstrated in this study.


American Journal of Sports Medicine | 2014

The Efficacy of Biceps Tenodesis in the Treatment of Failed Superior Labral Anterior Posterior Repairs

Frank McCormick; Benedict U. Nwachukwu; Dan Solomon; Christopher B. Dewing; Petar Golijanin; Daniel J. Gross; Matthew T. Provencher

Background: The incidence and arthroscopic treatment of superior labral anterior posterior (SLAP) tears have increased over the past decade. Recent evidence has identified factors associated with poor outcomes, including age, overhead activity, and concomitant rotator cuff tears. Biceps tenodesis has also been suggested as an alternative treatment to repair. Moreover, there are no studies demonstrating effective treatment strategies for failed type II SLAP repairs. Purpose: To prospectively evaluate the surgical outcomes of biceps tenodesis for patients who undergo elected revision surgery after an arthroscopically repaired type II SLAP tear. Study Design: Case series; Level of evidence, 4. Methods: After institutional review board approval, 46 patients who met failure criteria for an arthroscopically repaired type II SLAP tear elected to undergo open subpectoral tenodesis by 2 fellowship-trained surgeons from 2006 to 2010 at a tertiary care military treatment facility. Objective outcomes were preoperative and postoperative assessments with the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and Western Ontario Shoulder Instability Index (WOSI) scores and an independent physical examination. Statistical analysis was performed via analysis of variance. Results: Of the 46 patients, 42 completed the study (91% follow-up rate). The mean age of the patients was 39.2 years, 85% were male, and the mean follow-up period was 3.5 years (range, 2.0-6.0 years). The rate of return to active duty and sports was 81%. There was a clinically and statistically significant improvement across all outcome assessments after revision surgery (preoperative mean scores: ASES = 68, SANE = 64, WOSI = 65; postoperative mean scores: ASES = 89, SANE = 84, WOSI = 81) (P < .0001) and shoulder range of motion (preoperative mean values: forward flexion = 135°, abduction = 125°; postoperative mean values: forward flexion = 155°, abduction = 155°) (P < .0001). There was 1 case of transient musculocutaneous nerve neurapraxia. Conclusion: Biceps tenodesis is a predictable, safe, and effective treatment for failed arthroscopic SLAP tears at a minimum 2-year follow-up. The majority of patients obtained good to excellent outcomes using validated measures with a significant improvement in range of motion.


Arthroscopy | 2010

Glenohumeral joint preservation: current options for managing articular cartilage lesions in young, active patients.

Florian Elser; Sepp Braun; Christopher B. Dewing; Peter J. Millett

This is a review of joint-preservation techniques for the shoulder. Whereas the management of diffuse articular cartilage loss in the glenohumeral joints of elderly and less active patients by total shoulder arthroplasty is well accepted, significant controversy persists in selecting and refining successful operative techniques to repair symptomatic glenohumeral cartilage lesions in the shoulders of young, active patients. The principal causes of focal and diffuse articular cartilage damage in the glenohumeral joint, including previous surgery, trauma, acute or recurrent dislocation, osteonecrosis, infection, chondrolysis, osteochondritis dissecans, inflammatory arthritides, rotator cuff arthropathy, and osteoarthritis, are discussed. Focal cartilage lesions of the glenohumeral joint are often difficult to diagnose and require a refined and focused physical examination as well as carefully selected imaging studies. This review offers a concise guide to surgical decision making and up-to-date summaries of the current techniques available to treat both focal chondral defects and more massive structural osteochondral defects. These techniques include microfracture, osteoarticular transplantation (OATS [Osteochondral Autograft Transfer System]; Arthrex, Naples, FL), autologous chondrocyte implantation, bulk allograft reconstruction, and biologic resurfacing. As new approaches to glenohumeral cartilage repair and shoulder joint preservation evolve, there continues to be a heightened need for collaborative research and well-designed outcomes analysis to facilitate successful patient care.


Arthroscopy | 2008

An Analysis of the Rotator Interval in Patients With Anterior, Posterior, and Multidirectional Shoulder Instability

Matthew T. Provencher; Christopher B. Dewing; S. Josh Bell; Frank McCormick; Daniel J. Solomon; Timothy B. Rooney; Mark Stanley

PURPOSE To describe anatomic measurements of the rotator interval (RI) on magnetic resonance arthrogram (MRA) images and to assess the relationship between increased dimensions of the RI and instability conditions of the shoulder. METHODS Three groups of patients with clinical instability were treated arthroscopically (anterior [A = 19 patients], posterior [P = 14 patients], and multidirectional [M = 13 patients]), and a group of 10 control patients without clinical instability were also identified. The MRAs of all groups were randomized, and 5 blinded reviewers recorded RI anatomic measurements of: (1) sagittal measures of the distance between the subscapularis (SSc) and supraspinatus (SS) tendons at 3 anatomic landmarks across the RI, and (2) the sagittal position of the long head of the biceps (LHB) relative to the most anterior aspect of the SS. RESULTS The rotator interval distance between the SS and SSc tendons was nearly identical for all groups of instability, and was also not different from control groups. On the sagittal oblique sequences, the distance from the LHB tendon to the anterior edge of the SS tendon was significantly increased in posterior (7.4 mm) instability versus both the control group (2.4 mm; P = .025) and those with anterior instability (4.5 mm; P = .041), with the LHB in a consistent anterior position. The remainder of the measures was not statistically different between the groups. CONCLUSIONS The distance between the SS and SSc and the overall size of the RI was well preserved in all instability patterns and control conditions. The LHB tendon assumes a more anterior position relative to the supraspinatus tendon in patients with posterior instability versus those patients with anterior instability or those without clinical instability. Additional work is necessary to further define objective radiographic evidence of RI insufficiency in patients with shoulder instability. LEVEL OF EVIDENCE Level III, prognostic case-control study.

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Frank McCormick

Naval Medical Center San Diego

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Daniel J. Solomon

Naval Medical Center San Diego

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Lance E. LeClere

Naval Medical Center San Diego

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Peter J. Millett

Brigham and Women's Hospital

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Joseph Carney

Naval Medical Center San Diego

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Lance LeClere

Naval Medical Center San Diego

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Joseph R. Lynch

University of Washington Medical Center

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