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Dive into the research topics where Dean S. Louis is active.

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Featured researches published by Dean S. Louis.


American Journal of Sports Medicine | 1979

The saphenous nerve: its course and importance in medial arthrotomy

Letha Y. Hunter; Dean S. Louis; James R. Ricciardi; Gerald A. O'Connor

Both lower extremities of 10 cadavers (20 specimens) were dissected to delineate the course of the saphenous nerve and its two major divisions (sartorial and infrapatellar branches). The course of the saphenous nerve followed the standard text description, except at the point in the sartorius muscle where the infrapatellar branch exited to become a subcutaneous structure. The location of this branch varied slightly in each cadaver but was the same for both lower extremities in the same cadaver. The location of the sartorial nerve and its relationship to the tendons of the pes anserinus was consistent in all 20 specimens. Since 69% of a group of 75 patients found altered sensation significant after routine sectioning of the infrapatellar nerve following medial meniscectomy, a group of surgeons at the University of Michigan is now protecting the infrapatellar branch of the saphenous nerve at operation. Early results on a small number of patients indicate that no alteration in sensation occurs if the nerve is carefully retracted.


Journal of Hand Surgery (European Volume) | 1978

Assessing ulnar instability of the metacarpophalangeal joint of the thumb.

Andrew K. Palmer; Dean S. Louis

Seven hundred and fifty normal thumbs were examined to determine the normal range of radioulnar mobility of the metacarpophalangeal joint with the joint in full extension, 15 degrees of flexion, and full flexion. Full flexion was the position of greatest stability. Twenty-five adult unembalmed cadaver thumbs were examined to determine the optimal position for testing the metacarpophalangeal joint for ulnar collateral ligament stability. When radial stress was applied to the metacarpophalangeal joint of 20 specimens after cutting the adductor aponeurosis and capsule, minimal ulnar instability was found. However, further sectioning of the ulnar collateral ligament revealed marked ulnar instability most significantly when the thumbs were examined in full metacarpophalangeal flexion. Finally, division of the adductor aponeurosis, dorsal capsule, ulnar collateral ligament, accessory collateral ligament, and volar plate resulted in complete instability of the metacarpophalangeal joint in all positions tested.


Journal of Hand Surgery (European Volume) | 1984

Evaluation of normal values for stationary and moving two-point discrimination in the hand

Dean S. Louis; Thomas L. Greene; Kurt E. Jacobson; Christian Rasmussen; Patricia A. Kolowich; Steven A. Goldstein

Stationary and moving two-point discrimination were tested in a normal population stratified by age and sex. The 467 subjects tested consisted of 202 females and 265 males whose ages ranged from 4 years to 92 years. Statistical analysis of the data revealed the following: (1) Moving two-point values were of lesser magnitude than stationary two-point values in all areas tested; (2) test values for median innervated areas were lower by both methods than values for ulnar innervated areas; (3) there was a gradual increase in the magnitude of the test values for both methods with advancing age; (4) female subjects consistently tended to discriminate at shorter distances when compared with male subjects at corresponding sites; and (5) the absolute values obtained were dependent upon the individual examiner, but the statistical significance applied to the data of all of the examiners.


American Journal of Sports Medicine | 1986

Distal biceps brachii tendon avulsion: A simplified method of operative repair

Dean S. Louis; Fred M. Hankin; James F. Eckenrode; Patrick A. Smith; Edward M. Wojtys

Rupture of the distal insertion of the biceps brachii may lead to severe functional impairment of the upper ex tremity on the basis of resultant weakness of elbow flexion and supination. When the diagnosis of a post- traumatic distal biceps tendon avulsion is made, a simple method of reattachment is possible and func tionally warranted.


Journal of Bone and Joint Surgery, American Volume | 1974

Traumatic separation of the distal femoral epiphyseal cartilage plate.

David C. Stephens; Dean S. Louis

Twenty patients with fractures of the distal femoral epiphyseal cartilage were followed for an average of four years and three months. At the time of follow-up fifteen patients were skeletally mature. In four of the remaining five patients premature epiphyseal closure had developed. The more severe injuries progressed to premature closure of the growth plate. Five of fifteen Salter and Harris Type-II injuries resulted in shortening which averaged 2.3 centimeters. In four patients this occurred despite anatomically maintained reductions. This also occurred in one patient with a Type-I injury. Although Type-I and II injuries generally have an excellent prognosis for normal growth, this is not uniformly true of injuries to the distal femoral epiphyseal cartilage plate. Close follow-up of patients with these injuries is advocated.


Journal of Hand Surgery (European Volume) | 1985

Lipofibromas of the median nerve: Long-term follow-up of four cases

Dean S. Louis; Fred M. Hankin; Thomas L. Greene; Harold M. Dick

Four cases of lipofibromatous infiltration of the median nerve with long-term follow-up (average 11 years) are reported. Progressive compromise of median nerve function has been noted. Initial treatment considerations should be directed toward biopsy and alleviation of the compression neuropathy. The role of microsurgical debulking procedures remains unclear at this time.


Journal of Bone and Joint Surgery, American Volume | 1986

Rupture and displacement of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb. Preoperative diagnosis.

Dean S. Louis; J J Huebner; Fred M. Hankin

The evaluation and treatment of injuries of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb remain controversial. In a retrospective study that was done to assess our ability to determine whether displacement of the ligament (a Stener lesion) was present, we reviewed our accumulated experience with patients who had an injury of this ligament who were treated surgically between 1972 and 1984. Since our method of evaluation changed in 1977, we compared the preoperative and operative diagnoses in the twenty patients who were treated surgically from 1972 through 1976 with those in the twenty patients who were so treated from 1977 through 1984. Considering all forty patients who were treated operatively, sixteen (40 per cent) had a typical Stener lesion, and in two others (5 per cent) the ulnar collateral ligament was rolled up on itself and lying beneath the adductor aponeurosis. From 1972 through 1976, stability was tested with the metacarpophalangeal joint in complete extension or in varying amounts of flexion. Of the twenty thumbs that were evaluated by this technique and were treated surgically, 20 per cent had a Stener lesion. From 1977 through 1984, stability was tested with the joint in full flexion because of the findings in anatomical studies that were completed in 1977; the incidence of a Stener lesion in the twenty thumbs that were treated by repair or reattachment of the ligament during this time was 70 per cent.(ABSTRACT TRUNCATED AT 250 WORDS)


Journal of Hand Surgery (European Volume) | 1986

Scaphoid-trapezium-trapezoid fusion in the treatment of chronic scapholunate instability

James F. Eckenrode; Dean S. Louis; Thomas L. Greene

Limited intercarpal arthrodesis for chronic scapholunate instability has been the subject of several recent publications. We have followed nine patients, who had scapho-trapezio-trapezoidal (S-T-T) fusion for scapholunate instability. All nine patients were re-examined recently after an average follow-up period of 19 months (range, 12 to 25 months). Six of the nine patients believed that their symptoms were significantly improved. The postoperative range of wrist motion (ROM) was decreased in all directions of motion. The pinch strength averaged 86% on the treated side and the grip strength averaged 74% of the unoperated side. Review of follow-up x-ray films showed radiographic evidence of union in eight of nine patients. We conclude that, with careful patient selection and close attention to operative detail, S-T-T fusion can be an effective treatment for scapholunate instability. However, the results are not uniformly predictable, and neither range of motion nor strength is normal after the procedure.


Journal of Pediatric Orthopaedics | 1996

Open reduction and internal fixation of forearm fractures in children

Robert M. Ortega; Randall T. Loder; Dean S. Louis

We retrospectively reviewed 16 children younger than 13 years with 17 fractures of the shafts of the radius or ulna or both who had undergone an open reduction-internal fixation (ORIF). ORIF was performed when a closed reduction was deemed unacceptable in 14 radius fractures and for three unstable open fractures of the radius. The average age was 9.4 +/- 2.3 years (range, 5.0-12.5). Of the 14 fractures with an unacceptable closed reduction, soft-tissue interposition was encountered in seven. Fixation was secured by plates and screws, percutaneous Steinmann pins, or intramedullary Steinmann pins. There were no delayed unions or nonunions, no infections, and no neurovascular injuries. The average follow-up was 12.3 months; all 17 fractures had excellent results (forearm rotation loss of < 10 degrees). Our study indicates that excellent results can be expected with no increased risk of complications if the treating physician elects to proceed with an ORIF in a pediatric forearm fracture with proper indications.


Journal of Hand Surgery (European Volume) | 2012

Meta-analysis of Imaging Techniques for the Diagnosis of Complex Regional Pain Syndrome Type I

Zachary J. Cappello; Morton L. Kasdan; Dean S. Louis

PURPOSE To compare the effectiveness of imaging techniques in aiding and confirming the diagnosis of complex regional pain syndrome (CRPS) type I. METHODS We conducted a meta-analysis of randomized controlled studies that evaluated the effectiveness of 3 different imaging techniques in aiding the diagnosis of CRPS type I. A systematic search in bibliographical databases resulted in 24 studies with 1,916 participants. RESULTS To determine the effectiveness of each imaging technique, we determined the average specificity, sensitivity, negative predictive value, and positive predictive value and then statistically compared them using the analysis of variance statistical test, which indicated that compared with magnetic resonance imaging and plain film radiography, triple-phase bone scan had a significantly better sensitivity and negative predictive values. However, there appeared to be no statistical significance between imaging techniques when we evaluated specificity and positive predictive value using the analysis of variance test. CONCLUSIONS The findings of this meta-analysis support the use of triple-phase bone scan in ruling out CRPS type I, owing to its greater sensitivity and higher negative predictive value than both magnetic resonance imaging and plain film radiography. TYPE OF STUDY/LEVEL OF EVIDENCE Diagnostic I.

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Eugene Tsai

University of Michigan

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