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Biomedical subjects

E Lyle Cain

Publications and source records attributed to E Lyle Cain.

14 recordsLinked to original sources

Current concepts in the rehabilitation following articular cartilage repair procedures in the knee.

Postoperative rehabilitation programs following articular cartilage repair procedures will vary greatly among patients and need to be individualized based on the nature of the lesion, the unique characteristics of the patient, and the type and detail of each surgical procedure. These programs are based on knowledge of the basic science, anatomy, and biomechanics of articular cartilage as well as the biological course of healing following surgery. The goal is to restore full function in each patient as quickly as possible by facilitating a healing response without overloading the healing articular cartilage. The purpose of this paper is to overview the principles of rehabilitation following articular cartilage repair procedures. Furthermore, specific rehabilitation guidelines for debridement, abrasion chondroplasty, microfracture, osteochondral autograft transplantation, and autologous chondrocyte implantation will be presented based upon our current understanding of the biological healing response postoperatively.

Biomechanical Phenomena↗

Allograft reconstruction for massive, irreparable rotator cuff tears.

BACKGROUND: There is currently no widely accepted treatment for massive, irreparable rotator cuff tears. HYPOTHESIS: Allograft reconstruction to span the remaining defect in massive, irreparable rotator cuff tears will lead to increased functional results and will demonstrate healing of the allograft on follow-up magnetic resonance imaging studies. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1989 and 2003, 32 patients underwent allograft reconstruction of massive rotator cuff tears. University of California, Los Angeles shoulder scores were compared preoperatively and postoperatively and analyzed using paired Student t tests. In addition, 15 patients underwent postoperative magnetic resonance imaging to evaluate the structural integrity of the allograft reconstruction at the greater tuberosity insertion. RESULTS: Of 32 patients, 28 were available for review at a mean follow-up of 31.3 months; 23 of the 28 patients were satisfied with their outcome. There was 1 postoperative infection and 1 acute allograft rejection. The mean University of California, Los Angeles score increased from 12.1 preoperatively to 26.1 postoperatively (P < .001). All 15 patients evaluated with postoperative magnetic resonance imaging arthrograms demonstrated complete radiographic failure of the allograft rotator cuff reconstruction. Despite radiographic failure, the mean University of California, Los Angeles score increased from 13.2 preoperatively to 28.3 postoperatively in this subset of patients. CONCLUSION: The functional results of this reconstruction method are similar to those reported for debridement and subacromial decompression alone and are satisfactory, despite magnetic resonance imaging arthrogram evaluation demonstrating failure of the structural integrity of the allograft. Allograft reconstruction carries increased risk of infection and rejection and is technically more difficult than other less expensive treatment options with similar functional results. Therefore, we do not recommend allograft reconstruction of massive and otherwise irreparable rotator cuff tears.

Adult↗

Diagnosis, treatment, and rehabilitation of the thrower's elbow.

The overhead throwing motion generates enormous force in the elbow. Repetitive near failure loads lead to chronic adaptive changes and occasionally acute injury. The physician caring for the thrower must understand the complex anatomy and function of the elbow joint, along with the biomechanics of throwing, to accurately diagnose and treat elbow pathology. Evaluation of elbow pain in the throwing athlete must begin with a thorough and detailed throwing history including duration of symptoms, location of pain, timing during the phases of throwing motion, and associated symptoms. Physical examination should include inspection, range of motion, palpation, and specific tests to better define the pathology. A detailed history and physical examination will allow the astute clinician to obtain the proper diagnosis and start the appropriate operative or nonoperative treatment often without reliance on ancillary testing. Treatment and rehabilitation of these injuries must be tailored to the pathology present and focused towards a return to the athlete's activity.

Athletic Injuries↗

Effect of tibial tunnel dilation on pullout strength of semitendinosus-gracilis graft in anterior cruciate ligament reconstruction.

This biomechanical cadaver study evaluated the effect of tibial tunnel dilation on the pullout strength of semitendinosus and gracilis tendon grafts in anterior cruciate ligament reconstruction. Fourteen grafts were harvested, and the anterior cruciate ligament was reconstructed in the tibial and femoral tunnels. All femoral tunnels were reamed to the diameter of the graft. In seven knees, the tibial tunnels were reamed to the diameter of the graft. In the remaining seven knees, the tibial tunnels were reamed 2 mm smaller than the diameter of the graft and then serially dilated to the graft size using cannulated smooth dilators. Mechanical testing to graft failure was conducted. All grafts failed by graft pullout from the tibial tunnel. However, mean peak load was significantly higher for the dilated tibial specimens (616 +/- 263 N) than for the reamed specimens (453 +/- 197 N) (P = .0025).

Adult↗

Ulnar collateral ligament reconstruction in high school baseball players: clinical results and injury risk factors.

BACKGROUND: The incidence of ulnar collateral ligament injury has increased in baseball, especially at the high school level. HYPOTHESIS: Ulnar collateral ligament injury in high school baseball players is associated with overuse, high-velocity throwing, early throwing of breaking pitches, and improper warm-ups. STUDY DESIGN: Retrospective cohort study. METHODS: Follow-up physical examination and questionnaire data were collected at an average of 35 months after ulnar collateral ligament reconstruction from 27 former high school baseball players. Six potential risk factors were evaluated: year-round throwing, seasonal overuse, event overuse, throwing velocity more than 80 mph, throwing breaking pitches before age 14, and inadequate warm-ups. RESULTS: Overall, 74% returned to baseball at the same or higher level. Patients averaged 3 potential risk factors, and 85% demonstrated at least one overuse category. Of the pitchers, the average self-reported fastball velocity was 83 mph, and 67% threw breaking pitches before age 14. CONCLUSIONS: The success rate of ulnar collateral ligament reconstruction in high school baseball players is nearly equal to that in more mature groups of throwers. Overuse of the throwing arm and throwing breaking pitches at an early age may be related to their injuries. Special attention should be paid to elite-level teenage pitchers who throw with high velocity.

Adolescent↗

Correlation of interference screw insertion torque with depth of placement in the tibial tunnel using a quadrupled semitendinosus-gracilis graft in anterior cruciate ligament reconstruction.

PURPOSE: To evaluate the insertion torque of a soft-tissue interference screw in relation to depth of insertion into the tibial tunnel when used for fixation of a quadrupled semitendinosus-gracilis autograft in anterior cruciate ligament reconstruction. TYPE OF STUDY: Biomechanical cadaver study. METHODS: Ten quadrupled semitendinosus-gracilis grafts were harvested from fresh-frozen cadaver knees and fixed in donor proximal tibias using 10-mm bioabsorbable interference screws (Arthrex, Naples, FL). A cannulated torque screwdriver was used to measure screw insertion torque at 3 depths in the tibial tunnel: the outer cortex (distal third), the articular surface (proximal third), and between these 2 points (middle third). RESULTS: The mean insertion torques for the distal third, middle third, and proximal third were 8.7, 4.7, and 4.3 in/lb, respectively. The insertion torque was significantly higher at the outer cortex (distal third) than the middle third and proximal third (joint line of the tibial tunnel) ( P < .05). CONCLUSIONS: Our results indicate a correlation between insertion torque and depth of placement of bioabsorbable interference screws used for fixation of a semitendinosus-gracilis graft. Lower insertion torque at the articular surface, resulting in lower peak load or pullout strength, may outweigh the proposed benefits of joint-line fixation of a semitendinosus-gracilis graft used for anterior cruciate ligament reconstruction. CLINICAL RELEVANCE: Studies have suggested that anatomic proximal fixation of ACL grafts in the tibial tunnel produces stability similar to intact knees. The results of our study indicate that lower insertion torque at the articular surface results in lower peak load and pullout strength of the graft, which may outweigh the proposed benefits of joint-line fixation.

Adult↗

History and examination of the thrower's elbow.

Overhead throwing motion imparts enormous forces on the elbow. Repetitive near-failure loads lead to chronic adaptive changes and occasionally acute injury to bone, ligaments, and the elbow's muscle-tendon complexes. Physicians treating the thrower must thoroughly understand the complex anatomy and function of the elbow joint and throwing biomechanics to diagnose and treat elbow pathology. Evaluation of elbow pain begins with a thorough, detailed throwing history, including symptom duration, location of pain, timing during phases of throwing motion, and associated symptoms. Physical examination should include inspection, range of motion, palpation, and specific tests to better define the pathology. A detailed history and physical examination often lead the astute clinician to the proper diagnosis and treatment without reliance on ancillary testing.

Adolescent↗

Effect of fibular plate fixation on rotational stability of simulated distal tibial fractures treated with intramedullary nailing.

BACKGROUND: The effect of an intact fibula on rotational stability after a distal tibial fracture has, to the best of our knowledge, not been clearly defined. We designed a cadaver study to clarify our clinical impression that fixation of the fibula with a plate increases rotational stability of distal tibial fractures fixed with a Russell-Taylor intramedullary nail. METHODS: Seven matched pairs of embalmed human cadaveric legs and sixteen fresh-frozen human cadaveric legs, including one matched pair, were tested. To simulate fractures, 5-mm transverse segmental defects were created at the same level in the tibia and fibula, 7 cm proximal to the ankle joint in each bone. The tibia was stabilized with a 9-mm Russell-Taylor intramedullary nail that was statically locked with two proximal and two distal screws. Each specimen was tested without fibular fixation as well as with fibular fixation with a six-hole semitubular plate. A biaxial mechanical testing machine was used in torque control mode with an initial axial load of 53 to 71 N applied to the tibial condyle. Angular displacement was measured in 0.56-N-m torque increments to a maximal torque of 4.52 N-m (40 in-lb). RESULTS: Initially, significantly less displacement (p < or = 0.05) was produced in the specimens with fibular plate fixation than in those without fibular plate fixation. The difference in angular displacement between the specimens treated with and without plate fixation was established at the first torque data point measured but did not increase as the torque was increased. No significant difference in the rotational stiffness was found between the specimens treated with and without plate fixation after measurement of the second torque data point (between 1.68 and 4.48 N-m). CONCLUSIONS: Fibular plate fixation increased the initial rotational stability after distal tibial fracture compared with that provided by tibial intramedullary nailing alone. However, there was no difference in rotational structural stiffness between the specimens treated with and without plate fixation as applied torque was increased.

Aged↗

Management of intraoperative complications associated with autogenous patellar tendon graft anterior cruciate ligament reconstruction.

With the increasing number of anterior cruciate ligament (ACL) reconstructions being performed each year in the United States, sound surgical technique and preoperative planning are essential to decrease complications. Most intraoperative complications associated with ACL surgery are preventable with adequate planning and a reproducible surgical technique. When an autogenous bone-patellar tendon-bone graft is used for ACL reconstruction, pitfalls may occur at each step during the surgical procedure--preoperative assessment, graft harvest, notch preparation, tunnel preparation, graft passage and fixation, and rehabilitation. An array of options should be available for fixation of a patellar tendon graft, as well as alternative graft sources and graft preparation techniques.

Anterior Cruciate Ligament↗

Anatomic endoscopic anterior cruciate ligament reconstruction with patella tendon autograft.

Current tibial endoscopic ACL reconstruction techniques provide functional stability, but fall short of the ultimate goal of ACL reconstruction, to restore normal knee kinematics. Vertical graft placement results in restoration of normal anteroposterior stability with a negative Lachman exam, but may not produce a stable knee in rotation, noted by a positive pivot shift. The Clancy anatomic endoscopic ACL reconstruction technique utilizes flexible reamers to achieve anatomic graft placement to more closely reproduce normal knee function. The overall results of arthroscopic anatomic endoscopic ACL reconstruction are essentially the same as we have reported using our previous open and rear-entry, two-incision techniques for anatomic graft placement. The long-term benefits of a more physiologic single incision endoscopic ACL reconstruction are not yet determined; however, short-term results are encouraging.

Anterior Cruciate Ligament Injuries↗

Posterior olecranon resection and ulnar collateral ligament strain.

Valgus extension overload is well described in the throwing athlete. The surgical treatment involves posterior olecranon osteophyte resection. It is not known how much of the posterior olecranon can be resected before increased stress is placed on the ulnar collateral ligament. Ten cadaveric arms underwent posterior olecranon resection in 4-mm increments. After each bone resection, three different valgus loads were applied to the elbow at 70 degrees and 90 degrees of flexion. Ulnar collateral ligament strain significantly increased with each load. Significantly more strain occurred on the ulnar collateral ligament at 90 degrees compared with 70 degrees of elbow flexion. This difference may be the result of the relative importance of the ulnar collateral ligament and the posterior olecranon at different positions of elbow flexion. The strain on the ulnar collateral ligament was slightly higher after the 8-mm and 12-mm cuts but not statistically significant. This study suggests that at moderate quasistatic valgus loads, ulnar collateral ligament strain is not significantly increased with posterior olecranon resection.

Adult↗

Elbow injuries in throwing athletes: a current concepts review.

Repetitive overhead throwing imparts high valgus and extension loads to the athlete's elbow, often leading to either acute or chronic injury or progressive structural change. Tensile force is applied to the medial stabilizing structures with compression on the lateral compartment and shear stress posteriorly. Common injuries encountered in the throwing elbow include ulnar collateral ligament tears, ulnar neuritis, flexor-pronator muscle strain or tendinitis, medial epicondyle apophysitis or avulsion, valgus extension overload syndrome with olecranon osteophytes, olecranon stress fractures, osteochondritis dissecans of the capitellum, and loose bodies. Knowledge of the anatomy and function of the elbow complex, along with an understanding of throwing biomechanics, is imperative to properly diagnose and treat the throwing athlete. Recent advantages in arthroscopic surgical techniques and ligament reconstruction in the elbow have improved the prognosis for return to competition for the highly motivated athlete. However, continued overhead throwing often results in subsequent injury and symptom recurrence in the competitive athlete.

Athletic Injuries↗