Chad T Zehms

Naval Medical Center Portsmouth, Portsmouth, Virginia, United States

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Publications (8)15.96 Total impact

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    ABSTRACT: The purpose of this study was to quantify the change in degrees in the center-edge (CE) angle for each millimeter of acetabular rim resected in hips undergoing arthroscopic acetabular rim trimming. Preoperative and postoperative CE angle and millimeters of rim reduction were prospectively collected in 58 hips that underwent arthroscopic rim reduction. There were 35 women and 23 men. The mean age was 32 years. The inclusion criterion was hip arthroscopy for femoroacetabular impingement in patients without dysplastic hips. Two orthopaedic surgeons made independent measurements of the CE angle on preoperative and postoperative anteroposterior pelvis radiographs. To determine the amount of rim reduction intraoperatively, the lunate surface was measured with an arthroscopic ruler at the 12-o'clock position before and after rim trimming. The rim trimming was performed by a single surgeon using a 5.5-mm motorized bur. For the 58 hips included in this study, the mean rim reduction performed was 3.2 mm (range, 1 to 9 mm). The mean change in CE angle was 3.9 degrees (range, 0 degrees to 17 degrees ). All numbers were normally distributed. By use of a regression model, the change in the CE angle could be determined by the following formula: Change in CE angle = 1.8 + (0.64 x rim reduction in millimeters). The interobserver intraclass correlation coefficient for radiographic measurement of the CE angle was 0.92 (95% confidence interval, 0.87 to 0.95), indicating excellent interobserver reliability. The amount of change in the CE angle can be estimated by the amount of bony resection performed at the 12-o'clock position on the lunate surface in the arthroscopic treatment of femoroacetabular impingement. We found that 1 mm of bony resection equals 2.4 degrees of change in the CE angle and 5 mm of bony resection equals 5 degrees of change in the CE angle. Level II, diagnostic study.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 06/2010; 26(6):757-61. · 3.10 Impact Factor
  • Arthroscopy The Journal of Arthroscopic and Related Surgery 01/2009; 25(6):e18. · 3.10 Impact Factor
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    ABSTRACT: There is considerable controversy regarding whether a double-bundle reconstruction of the posterior cruciate ligament is superior to single-bundle techniques. The purpose of this study was to compare posterior tibial translation and external rotation following double and single-bundle tibial inlay reconstruction of the posterior cruciate ligament in both a posterolateral corner-deficient and a repaired cadaver model. Posterior drawer testing, dial testing, and stress radiography were performed on nine cadaver knees. The intact knees served as controls. The posterior cruciate ligament and the posterolateral corner structures were resected, and each knee then underwent a double-bundle reconstruction of the posterior cruciate ligament. Following testing, both with and without the posterolateral corner repaired, the posteromedial bundle was released and the knee was retested with a single-bundle reconstruction. With dial testing, external rotation measured a mean (and standard error) of 7.6 degrees +/- 0.4 degrees at 30 degrees of knee flexion and 9.0 degrees +/- 0.8 degrees at 90 degrees after the double-bundle reconstruction with posterolateral corner repair, and it measured 11.2 degrees +/- 1.4 degrees at both 30 degrees and 90 degrees after the single-bundle reconstruction with posterolateral corner repair. When dial testing was performed after the double-bundle reconstruction without posterolateral corner repair, external rotation measured a mean of 15.8 degrees +/- 1.9 degrees at 30 degrees and 16.9 degrees +/- 2.0 degrees at 90 degrees; after the single-bundle reconstruction without posterolateral corner repair, it measured 20.1 degrees +/- 1.8 degrees at 30 degrees and 20.3 degrees +/- 1.7 degrees at 90 degrees. Without posterolateral corner repair, the double-bundle reconstruction permitted significantly less external rotation than did the single-bundle reconstruction at 30 degrees (p = 0.03). Stress radiography showed the mean posterior displacement after the double-bundle reconstruction with posterolateral corner repair to be 3.3 +/- 1.4 mm. This value was not significantly different from the mean posterior displacement of 4.8 +/- 1.0 mm after the single-bundle reconstruction with posterolateral corner repair, and both values were similar to that for the intact control (2.9 +/- 0.5 mm) (p = 0.254). However, the single-bundle reconstruction without posterolateral corner repair was associated with significantly increased posterior displacement when compared with the intact controls (p = 0.039) and with the double-bundle reconstruction without posterolateral corner repair (p = 0.026). Double-bundle reconstruction of the posterior cruciate ligament offers measurable benefits in terms of rotational stability and posterior translation in the setting of an untreated posterolateral corner injury. With the posterolateral corner intact, at time zero, the double-bundle reconstruction used in this study provided more rotational constraint to the knee at 30 degrees and it did not further reduce posterior translation.
    The Journal of Bone and Joint Surgery 10/2008; 90(9):1820-9. · 3.23 Impact Factor
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    ABSTRACT: The treatment of symptomatic posterior cruciate ligament injuries of the knee is controversial. Identification of concomitant injuries of the posterolateral corner is important to optimize surgical and clinical outcomes, although this diagnosis is sometimes difficult. The purpose of this study was to determine the physical examination and stress radiography parameters of isolated injuries of the posterior cruciate ligament and combined injuries of the posterior cruciate ligament and posterolateral corner. Our hypothesis was that Grade-3 posterior drawer laxity is an indicator of a concomitant injury of the posterolateral corner. Ten pairs of cadaver knees (a total of twenty knees) were evaluated with posterior drawer testing, dial testing, and stress radiography. Stress radiography was performed by applying a 200-N posterior drawer at 90 degrees of knee flexion. The knees were tested while intact and then retested following the sequential resection of the posterior cruciate ligament followed by the posterolateral corner structures. All intact specimens were rated as Grade 0 on posterior drawer testing. Sectioning of the posterior cruciate ligament resulted in Grade-2 posterior drawer in all specimens. The additional resection of the posterolateral corner resulted in Grade-3 posterior drawer in all specimens. Dial testing of the intact knees resulted in a mean (and standard error) of 10.5 degrees +/- 1.0 degrees and 10.5 degrees +/- 0.80 degrees of external rotation at 30 degrees and 90 degrees, respectively. This increased significantly to 15.1 degrees +/- 1.1 degrees and 16.2 degrees +/- 0.89 degrees, respectively, following sectioning of the posterior cruciate ligament (p < 0.05). After resection of the posterolateral corner, rotation was further increased to a mean of 21.6 degrees +/- 1.5 degrees at 30 degrees and 27.5 degrees +/- 1.6 degrees at 90 degrees (p < 0.05). On stress radiography, the average posterior displacements measured 2.9 +/- 0.5 mm in the intact specimens, 12.7 +/- 1.0 mm after resection of the posterior cruciate ligament, and 22.3 +/- 1.6 mm after the additional resection of the posterolateral corner (p < 0.05). The corrected posterior displacement, calculated by subtracting the displacement in the intact knees, was 9.8 mm after resection of the posterior cruciate ligament and 19.4 mm after the additional resection of the posterolateral corner. A grade of 3 on posterior drawer testing and >10 mm of posterior tibial translation on stress radiography correlate with the presence of a posterolateral corner injury in addition to a complete disruption of the posterior cruciate ligament.
    The Journal of Bone and Joint Surgery 08/2008; 90(8):1621-7. · 3.23 Impact Factor
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    ABSTRACT: The ideal surgical management of isolated and combined posterior cruciate ligament (PCL) injuries is controversial. One active debate concerns the advantages of an open tibial inlay technique versus an arthroscopic transtibial tunnel technique. Therefore, the goal of this study is to biomechanically compare arthroscopic and open double-bundle PCL tibial inlay procedure with and without posterolateral corner (PLC) deficiency. Ten matched pairs of cadaveric knees were randomly assigned to undergo PCL sectioning and reconstruction using either the open inlay or arthroscopic inlay approach. Clinical testing consisted of posterior drawer, TELOS stress testing, and dial testing at both 30 degrees and 90 degrees . The knee conditions tested were intact, after PCL sectioning, after PLC release, and following PCL reconstruction, with and without the PLC repair. Both 1-way repeated measures and 2-way mixed design analyses of variance were used to determine differences between the knee conditions, with significance set at P < .05. After PCL and PLC reconstruction, 10 of 10 open specimens and 9 of 10 arthroscopic specimens were a grade 0 posterior drawer. The remaining arthroscopic specimen was grade I. The average radiographic posterior displacement for arthroscopic and open reconstructions (PCL+/PLC+) was 3.9 and 2.7 mm, respectively, with no significant difference. However, if the PLC was deficient (PCL+/PLC-), the translation for arthroscopic and open specimens increased to 8.5 and 6.5 mm, respectively, and was statistically different from the intact state but not from each other. At 30 degrees of knee flexion, both the open and arthroscopic specimen averaged 8.4 degrees of external rotation. At 90 degrees of knee flexion, the external rotation measurements increased to 9.6 degrees and 9.3 degrees in the arthroscopic and open groups, respectively. Additionally, there was no significant difference in external rotation between intact and reconstructed knees with either group. The arthroscopic method of double-bundle inlay PCL reconstruction provides comparable stability to the open inlay using clinically relevant measurement tools both in the PLC intact or deficient state. This novel arthroscopic double-bundle PCL inlay reconstruction provides comparable stability to the open approach with a potential for lower operative morbidity.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 05/2008; 24(4):472-80. · 3.10 Impact Factor
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    ABSTRACT: Hip pain in the athlete is increasing in prevalence. Proper diagnosis and treatment is important in returning these athletes to play as soon as possible. With the advent of new flexible instruments and better diagnostic application, the orthopaedic surgeon is able to effectively treat patients with capsular laxity. The causes of capsular laxity and clinical instability can be, but are not limited to, traumatic injury, a traumatic gradual onset, and bony abnormality. The diagnosis of instability includes a complete clinical physical exam including the posterior impingement test, laxity examination, Dial test, and axial distraction/apprehension test. Arthroscopic intervention for the treatment of hip instability is aimed at correction of the capsular pathology through the use of the radiofrequency probe and plication sutures. Outcomes following the treatment of capsular laxity and instability of the hip include the analysis of outcome scores used for hip arthroscopy including the Modified Harris Hip Score, and Hip Outcome Score sports and activities of daily living subscale. Knowledge of causative factors and the clinical presentation of hip instability are valuable in the accurate diagnosis and arthroscopic treatment. Arthroscopic management of hip instability has shown promising results.
    Operative Techniques in Sports Medicine 10/2007; · 0.18 Impact Factor
  • Chad T Zehms, Luke Balsamo, Robert Dunbar
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    ABSTRACT: Coaptation splinting is an accepted form of treatment for humeral shaft fractures in both children and adults. However, application may be difficult when working alone or with an uncooperative patient. We describe a modified method, involving supplies easily found in most emergency departments and cast rooms, that mitigates these problems.
    American journal of orthopedics (Belle Mead, N.J.) 11/2006; 35(10):452-4.
  • Jon K. Sekiya, Chad T. Zehms
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    ABSTRACT: Recurrent glenohumeral instability can be a debilitating condition that affects an athlete’s ability to compete at the highest levels of competition and, in our military population, meet the demands of active military service. Significant advances in the understanding of the natural history of this condition have led to new operative interventions and rehabilitative protocols that aim to return the athlete to their previous level of activity. There has been increased interest in the arthroscopic stabilization of shoulder instability, which is evolving from first-time dislocators to recurrent instability in noncontact and contact athletes as well. A thorough understanding of the pathoanatomy involved in shoulder instability allows us to address all injured structures responsible for recurrent instability including the Bankart tear (reverse Bankart for posterior instability) and loss of capsuloligamentous tension. As our arthroscopic techniques continue to improve, our clinical results will approach that of traditional open techniques with perhaps less perioperative morbidity and loss of motion. We have presented one such arthroscopic technique of a multipleated plication through a single anterior and posterior portal that has served us well in the management of recurrent shoulder instability. At present, the only contra-indication to an arthroscopic procedure is significant bony defects of the humeral head or glenoid, which requires a more extensive intervention.
    Operative Techniques in Sports Medicine - OPERAT TECHNIQ SPORTS MED. 01/2005; 13(4):189-195.