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Darren L Johnson

Publications and source records attributed to Darren L Johnson.

At least 19 recordsLinked to original sources
PubMed2005

Arthroscopic patellar "bankart" repair after acute dislocation.

We present a case of acute patellar dislocation in a skeletally immature patient treated with arthroscopic medial patellofemoral ligamentous complex repair using suture anchors with a horizontal mattress suture technique. Patellar dislocation is a common problem in the skeletally immature. Treatment is controversial for first-time dislocators because of the high rate of recurrent instability and functional disability in these patients. Surgical repair of the medial restraints may decrease recurrent instability, although anterior knee pain and crepitus is a common finding after open surgical techniques. Arthroscopic medial retinacular imbrication has been described for patients with persistent instability with good short-term results. Acute dislocations may cause avulsion of the medial patellofemoral ligamentous complex from the patella; this is amenable to direct primary repair to prevent recurrent instability and avoid the morbidity of open surgery. This technique recreates normal anatomy and function with minimally invasive surgery.

Adolescent↗
PubMed2005

Soft-tissue interference fixation: bioabsorbable screw versus metal screw.

PURPOSE: To compare the biomechanical properties of eccentrically positioned bioabsorbable and titanium interference screws for quadrupled hamstring tendon graft (QHTG) fixation. TYPE OF STUDY: In vitro, biomechanical study. METHODS: In 10 paired cadaveric tibiae and femurs (mean age, 66.5 years; range, 53 to 81 years), QHTG fixation was performed in tunnels sized to within 0.5 mm of QHTG diameter using either a titanium (RCI; Smith & Nephew Donjoy, Carlsbad, CA) or a bioabsorbable (BioScrew; Linvatec, Largo, FL) screw of equal size. Constructs then underwent biomechanical load-to-failure testing on a servo-hydraulic device at 20 mm/min. RESULTS: Load at failure was greater for femoral-side QHTG fixation using the bioabsorbable screw than the titanium screw (486 +/- 223.7 N v 246 +/- 99.1 N, P = .006); however, displacement did not differ (P = .81). There were no statistically significant differences between groups for tibial side load at failure (P = .54), stiffness (P = .44), or displacement (P = .50). Screw thread-induced graft laceration was more frequently observed in the titanium screw group (9 of 10 grafts during femoral-side testing, 0 of 10 grafts during tibial-side testing) than in the bioabsorbable screw group (0 of 10 grafts during femoral-side testing, 1 of 10 grafts during tibial-side testing). CONCLUSIONS: BioScrew interference screw fixation was comparable or superior to RCI titanium interference screw fixation. BioScrew interference screw fixation also produced less screw thread-induced laceration of the QHTG during load-to-failure testing. CLINICAL RELEVANCE: Use of a biodegradable interference screw positioned directly against a soft-tissue graft provides fixation properties similar to those of a metal interference screw.

Absorbable Implants↗
PubMed2005

Summer fun.

Explore the source record for details and available documents.

Athletic Injuries↗
PubMed2005

Spondylolysis and spondylolisthesis in the athlete.

Though athletes may be able to return to their sport after treatment of spondylolysis and spondylolisthesis, prevention of back injury in at-risk patient athletes should be the treating physician's primary goal.

Humans↗
PubMed2004

Fracture of the femoral tunnel after an anterior cruciate ligament reconstruction.

Fractures after anterior cruciate ligament (ACL) reconstructive surgery are rare. Patella fractures can occur as a complication after bone-patellar tendon-bone autografts, and few case reports of tibia fractures have been published. Although reports of femur fractures have been published, the causes are attributed to stress risers other than the femoral tunnel. To our knowledge, this is the first case report of a femoral tunnel serving as a stress riser after an ACL reconstruction with bone-patellar tendon-bone autograft. The patient's fracture resulted from minimal trauma and required surgical fixation.

Accidental Falls↗
PubMed2004

The value of clinical examination versus magnetic resonance imaging in the diagnosis of meniscal tears and anterior cruciate ligament rupture.

PURPOSE: The purpose of this study was to compare the accuracy of clinical examination versus magnetic resonance imaging (MRI) in diagnosing meniscal and anterior cruciate ligament (ACL) pathology. TYPE OF STUDY: Prospective, longitudinal study. METHODS: Between August 2001 and December 2001, we prospectively evaluated 50 consecutive patients (37 male, 13 female) with 65 pathologies of medial meniscal tears, lateral meniscal tears, and/or ACL rupture. The average preoperative period for the patients was 5 weeks (range, 5 days to 5 months) and their mean age was 22 years (range, 12 to 42 years). After initial clinical examination, the same sports medicine fellowship-trained orthopaedic surgeon (10-year practice profile of 100% sports medicine) evaluated the MRI of the patients and performed their arthroscopic procedure. Accuracy, sensitivity, specificity, and positive and negative predictive values were calculated comparing clinical examination, MRI, and arthroscopic evaluation. RESULTS: There was no statistical difference between MRI or clinical examination in diagnosing medial or lateral meniscal tears or ACL tears ( P >.05). The accuracy of the clinical examination and MRI evaluation was equal for diagnosing meniscal tears and ACL ruptures. CONCLUSIONS: A well-trained qualified surgeon can safely rely on clinical examination for diagnosing meniscal and ACL injuries. Clinical examination is at least as accurate as MRI in the skilled orthopaedic surgeon's hand. MRI should be reserved for more complicated and confusing cases. The routine ordering of an MRI scan of the knee before examination by a well-trained orthopaedic surgeon is not recommended. LEVEL OF EVIDENCE: Level II, diagnostic.

Adolescent↗
PubMed2004

Outcomes in patients with pathological carcinoma in situ only disease at radical cystectomy.

PURPOSE: Pathological stage influences patient outcome after radical cystectomy. We present our experience with patients who have only transitional cell carcinoma in situ of the bladder (pCIS-only) on final pathological examination after radical cystectomy. MATERIALS AND METHODS: Between August 1995 and June 2003, 576 patients underwent radical cystectomy at our institution. Of these patients 54 were pathological stage CIS-only on final cystectomy specimen. Four patients simultaneously had invasive transitional cell carcinoma of the ureter or renal pelvis and were excluded from evaluation. Variables examined included demographic characteristics, preoperative pathological stage, high risk features and followup parameters. RESULTS: Of the 50 patients with pCIS-only 44 (88%) were disease-free at last followup. Mean followup was 37.2 months (range 3.6 to 93.5). Of the 50 patients 21 had focal CIS while 29 had multifocal disease. There was no difference in disease recurrence between these 2 groups (9.5% vs 13.7%, p = 0.8). There were 9 patients with proximal urethral CIS involvement, of whom metastatic disease developed in 3. Only 1 of the 8 patients (12.5%) with ureteral orifice involvement had recurrence. Of the 50 patients 22 had muscle invasive disease on initial transurethral resection without residual invasive disease at cystectomy. This subset fared significantly worse after radical cystectomy than the 28 patients with less than stage T2 disease on transurethral bladder tumor resection (22.7% vs 3.6% metastasis, p < or = 0.05). CONCLUSIONS: The outcome of patients who have pCIS-only after radical cystectomy is not uniform. Patients may be at higher risk for recurrence if disease extends to the proximal urethra. In addition, patients demonstrating invasion on clinical staging (stage T2 or greater) but subsequent pCIS-only disease have a worse prognosis compared to those with superficial clinical staging. Patients with CIS-only on clinical and pathological staging have an excellent disease-free survival with radical cystectomy even with the presence of multifocal disease.

Adult↗
PubMed2004

Tunnel enlargement after anterior cruciate ligament surgery.

Bone tunnel enlargement has been reported after anterior cruciate ligament (ACL) reconstruction surgery. Although the long-term outcome of this phenomenon is not yet known, tunnel lysis or expansion may be clinically significant in revision surgery because the enlarged tunnels may complicate graft placement and fixation. There any many proposed theories for tunnel lysis. The most accurate statement is that this condition has a multifactorial etiology. Mechanical and biological causes have been reported, and both contribute to enlarged graft tunnels. This article describes the multiple causes of bone tunnel enlargement after ACL surgery. Future techniques and advances in primary ACL surgery must seek to eliminate this phenomenon.

Anterior Cruciate Ligament↗
PubMed2004

Functional assessment using the step-up-and-over test and forward lunge following ACL reconstruction.

This investigation compared lower extremity function of a control group and a group of patients who underwent anterior cruciate ligament (ACL) reconstruction using a repeated measures post-test only control group design. The ACL reconstruction group consisted of 18 patients at least 6 months postoperative (mean 58+/-19 weeks) and the control group consisted of 18 healthy, recreationally active individuals. Both groups performed a step-up-and-over test and a forward lunge on a long force plate. During the step-up-and-over test, the control group produced significantly more force during the initial step than the ACL reconstruction group. Also, when the ACL reconstruction patients led with the involved extremity, they were significantly slower. During the forward lunge test, the impact index and force impulse measurements were significantly greater for the uninvolved leg than the involved leg in the ACL reconstruction group. The implications are that force generation during functional tests may remain compromised for >1 year following reconstruction. The aforementioned tests are promising for evaluation of function following ACL reconstruction.

Adult↗
PubMed2004

Sideline management of acute knee injuries.

Sideline management of acute knee injuries requires medical personnel to have knowledge of injury patterns, mechanisms, physical findings, and treatment strategies. Fractures and multiple-ligament injured knees need to be rapidly diagnosed and stabilized to allow for timely transfer to a location where further evaluation and definitive treatment can be provided.

Acute Disease↗
PubMed2003

Shoulder instability with absence of the long head of the biceps tendon.

We present a case of a 25-year-old woman undergoing arthroscopy for multidirectional instability. She was found to have a complete absence of the long head of the biceps tendon, thought to be congenital. It is hypothesized that the absence of the biceps may have played a role in the instability.

Adult↗