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David P Richards

Publications and source records attributed to David P Richards.

16 recordsLinked to original sources
PubMed2006

New sutures and suture anchors in sports medicine.

Arthroscopic surgery requires appropriate surgical implants for effective fixation of tendons and ligaments to bone. Biodegradable suture anchors are being used with increasing frequency for various procedures in sports medicine. As companions to these biodegradable suture anchors, new sutures have been developed which possess greater strength and different material properties from the conventional braided polyester suture. Biodegradable polymers currently found in sutures and suture anchors include poly-L-lactic acid, poly-D, L lactic acid, polydioxanone, polyglycolic acid and their copolymers. Suture anchors are now available preloaded with a choice of conventional braided polyester sutures or some version of ultrahigh molecular weight polyethylene ("super") sutures. Most new suture anchors come with 2 sutures. The manner in which these sutures are attached to the anchor varies and may consist of 2 separate eyelets or 2 slots either parallel to one another or at different angles to one another. Some anchors have a very large single eyelet that allows for 2 or more sutures.

Arthroscopy↗
PubMed2005

A biomechanical analysis of two biceps tenodesis fixation techniques.

PURPOSE: To assess and compare the biomechanical properties and load-to-failure of 2 biceps tenodesis fixation techniques, interference screw fixation and double suture anchor fixation. TYPE OF STUDY: Biomechanical study. METHODS: Eleven fresh-frozen human cadaveric specimens were used in this study. A biceps tenodesis was performed using 1 of 2 techniques, interference screw fixation or double suture anchor fixation. A 7-mm interference screw was used in 5 cadaveric trials. A double suture anchor technique was performed in 6 cadaveric specimens. The tenodesis construct in each specimen was loaded to failure using a Servohydraulic materials test system (MTS Model 858; Bionix, MTS Corp, Minneapolis, MN). Each specimen was loaded at 5 mm/second with a preload of 5 N with the vector of pull distally in line with the long axis of the humerus. Each specimen was then loaded until failure of the repair occurred. Statistical analysis of the interference screw group compared with the suture anchor group was performed using a Student t test. RESULTS: The mode of failure of the interference screw group was variable, but the suture anchor group consistently failed at the anchor or anchor eyelet. The average pullout strength of the suture anchor group was 135.5 +/- 37.8 N whereas the failure load in the interference group was 233.5 +/- 55.5 N. The interference group had a significantly greater resistance to pullout than the suture anchor group (P = .007). CONCLUSIONS: Based on these results, a biceps tenodesis using an interference screw will provide greater fixation strength than a biceps tenodesis performed with a double suture anchor technique. CLINICAL RELEVANCE: The surgeon treating biceps tenodesis may wish to choose a fixation technique with higher initial strength (interference screw instead of double suture anchor) to lessen the chance of early failure, particularly if the patient begins early active elbow flexion.

Adult↗
PubMed2005

Relation between narrowed coracohumeral distance and subscapularis tears.

PURPOSE: To determine whether coracohumeral distance was significantly narrowed in the presence of a torn subscapularis. TYPE OF STUDY: Retrospective cohort study. METHODS: The coracohumeral distance of a consecutive series of patients (n = 35, 36 shoulders) requiring an arthroscopic repair of the subscapularis was compared with a control group (n = 35). The control group consisted of patients who underwent shoulder arthroscopy but who did not have any rotator cuff, subscapularis, or subcoracoid pathology. The coracohumeral distance was measured from the tip of the coracoid to the cortex of the proximal humerus on an axial cut of preoperative magnetic resonance imaging. A Student t test was used to determine the statistical differences between the 2 groups. RESULTS: The average coracohumeral distance in the subscapularis group was 5.0 +/- 1.7 mm and the average coracohumeral distance in the control group was 10.0 +/- 1.3 mm. Statistical analysis, using the Student t test, showed that the coracohumeral distance was significantly narrowed in the group of patients with a torn subscapularis. CONCLUSIONS: These results show a significant relationship between a narrowed coracohumeral distance and subscapularis pathology. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Aged↗
PubMed2005

Compressive loads in longitudinal lateral meniscus tears: a biomechanical study in porcine knees.

PURPOSE: To determine the displacement forces across a lateral meniscal tear during motion. TYPE OF STUDY: Experimental laboratory biomechanical study. METHODS: A middle third longitudinal lateral meniscal cut was created arthroscopically at the "red-white" junction in 5 intact porcine knees. With a pressure transducer in the tear, the knees were repeatedly cycled through a full range of motion. Pressure data were gathered with the knees held at neutral, internal rotation (IRot), and external rotation (ERot) and matched to the specific flexion angle measured by electronic goniometer. Averaged pressure measurements were calculated at each 5 degrees interval. RESULTS: The highest pressures were seen at full extension (neutral, 589 mm Hg; IRot, 1,110 mm Hg; ERot, 337 mm Hg) and declined to a low at 90 degrees of flexion (neutral, 133 mm Hg; IRot, 314 mm Hg; ERot, 187 mm Hg). Then the pressures increased steadily after 100 degrees as the knees were further flexed. The highest pressure was always seen with IRot. IRot during flexion resulted in higher lateral meniscus compressive loads than ERot. CONCLUSIONS: This model demonstrated that a middle third longitudinal lateral meniscal cut is compressed throughout the full range of knee motion. At no time were negative intrameniscal tear pressures registered that would suggest meniscal cut separation. CLINICAL RELEVANCE: These data suggest that meniscal compressive loads, not distractive loads, occur throughout knee flexion and extension. The absence of distractive loads across a meniscal cut suggests that the ability of a repair to align the meniscal fragment may be more important than a high load to failure strength.

Animals↗
PubMed2005

Use of preoperative magnetic resonance imaging to predict rotator cuff tear pattern and method of repair.

PURPOSE: To determine the magnetic resonance imaging (MRI) criteria for predicting rotator cuff tear pattern and method of repair. TYPE OF STUDY: Retrospective MRI/arthroscopy correlation. METHODS: Sixty-six preoperative MRI scans were evaluated. The maximum medial to lateral length (L) of the tear was measured on T2-weighted coronal cuts. The maximum anterior to posterior width (W) was measured on T2-weighted sagittal cuts. The cases were divided into 3 groups: group 1, short-wide tears, L < or = W, L < 2 cm; group 2, long-narrow tears, L > W, W < 2 cm; and group 3, long-wide tears, L > or = 2 cm, W > or = 2 cm. RESULTS: Of the 66 MRI scans, 55 were adequate for standardized measurement. Group 1, 16 cases: 15 were found at arthroscopy to be crescent-shaped tears repaired end-to-bone; 1 was repaired with interval slides. Group 2, 22 cases: all 22 were repaired side-to-side/margin convergence. Group 3, 17 cases: 12 required interval slides, 1 partial repair was performed, and 4 were repaired side-to-side/margin convergence. CONCLUSIONS: Tear pattern and method of repair can be predicted on high-quality MRI scan. Group 1, L < or = W and L < 2 cm, predicts a crescent-shaped tear and end-to-bone repair (positive predictive value, 93.8%). Group 2, L > W and W < 2 cm, predicts a longitudinal tear and side-to-side/margin convergence repair (positive predictive value 100%). Group 3, L > or = 2 cm and W > or = 2 cm, predicts a massive contracted tear and that primary end-to-bone or side-to-side repairs are usually not possible and that interval slides or partial repair may be necessary (positive predictive value, 76.5%). The overall diagnostic model based on usable MRI scans significantly predicted arthroscopic findings (P < .001 for chi-square test). LEVEL OF EVIDENCE: Level III, development of diagnostic criteria with universally applied reference (nonconsecutive patients).

Adult↗
PubMed2004

Load to failure testing of new meniscal repair devices.

PURPOSE: New all-inside meniscal repair devices include those combining sutures with anchors and that allow for an "adjustable" repair. This study's purpose was to compare the failure strength of new meniscal repair devices with suture repairs. TYPE OF STUDY: Experimental laboratory biomechanical study. METHODS: A single repair was placed in a vertical longitudinal peripheral tear made in fresh adult porcine menisci. Group 1 had a vertically oriented suture using the FasT-Fix (Smith & Nephew Endoscopy, Andover, MA) device. Group 2 had a horizontally oriented mattress suture using the FasT-Fix device. Group 3 had a repair using 2 Arthrex (Naples, FL) meniscal darts. The Group 4 repair used a RapidLoc (Mitek Surgical Products, Westwood, MA) device. The Group 5 repair used the Arthrotek meniscal screw (Biomet, Warsaw, IN). Group 6 had a single vertical suture, and group 7 a single horizontal suture, both of 2-0 Mersilene (Ethicon, Somerville, NJ). Load to failure testing was performed. RESULTS: The vertical FasT-Fix suture had a mean load to failure of 70.9 N (1 SD +/- 33). The horizontal FasT-Fix suture had a mean load to failure of 72.1 N (+/- 23.5). The double Dart repair had a mean load to failure of 61.7 N (+/- 19). The RapidLoc repair had a mean load to failure of 43.28 N (+/- 3.98). The Arthrotek meniscal screw repair had a mean load to failure of 28.09 N (+/- 7.93). Failure occurred with device pullout of the inner rim (9 of 10) for the Darts, device pullout of the inner rim (6 of 10) and pullout of the outer rim (4 of 10) for the Arthrotek screw, and suture breakage for the FasT-Fix and the RapidLoc devices. The vertical sutures' mean load to failure was 80.43 N (+/- 8.5), and all 13 failed by suture breaking. The horizontal sutures' mean failure load was 55.9 N (+/- 18.8), and failure was by both suture breaking (6 of 10) and pulling through the meniscal tissue (4 of 10). CONCLUSIONS: Some of the newer meniscal repair devices show improved loads to failure over earlier generations.

Animals↗
PubMed2004

Arthroscopic humeral avulsion of the glenohumeral ligaments (HAGL) repair.

Humeral avulsion of the glenohumeral ligaments (HAGL lesion) is one of the pathologic lesions that occurs secondary to anterior glenohumeral instability. Although HAGL lesions occur less commonly than Bankart lesions in cases of anterior instability, it is necessary to understand this pathology and to make the necessary repair. An all-arthroscopic technique using suture anchors can be used to repair HAGL lesions, but it is a difficult and demanding technique. To facilitate this type of repair, the surgeon must be: (1) comfortable with both the 30 degrees and 70 degrees arthroscopes, (2) able to establish and use the 5-o'clock portal, (3) able to abduct and externally rotate the arm, and (4) able to ensure secure fixation of the glenohumeral ligaments to bone through adequate knot and loop security.

Acute Disease↗
PubMed2004

Arthroscopic-assisted biceps tenodesis for ruptures of the long head of biceps brachii: The cobra procedure.

A number of open procedures have been presented in the literature that described the repair of the ruptured long head of biceps brachii (LHBB). Although arthroscopic biceps tenodesis techniques have been used to address partial tears or subluxation of the biceps, no arthroscopic technique to assist in the treatment of complete retracted ruptures of the LHBB has been described. This article describes an arthroscopic-assisted biceps tenodesis, using interference screw fixation, in the treatment of acute or chronic LHBB ruptures. An arthroscopic-assisted biceps tenodesis with interference screw fixation provides an alternative to open LHBB tenodesis. The ability to tenodese the retracted LHBB arthroscopically is a technologic advance that could reduce morbidity in comparison to open tenodesis, thus resulting in a better functional outcome.

Absorbable Implants↗
PubMed2004

Relation between adhesive capsulitis and acromial morphology.

PURPOSE: The purpose of this study was to determine whether a relationship existed between primary adhesive capsulitis and acromial morphology. TYPE OF STUDY: Case control series. METHODS: Between January 1999 and June 2002, a total of 100 patients (104 shoulders) were diagnosed with adhesive capsulitis. A retrospective chart review was performed of all of these patients. A total of 67 patients (69 shoulders) met the inclusion criteria of primary adhesive capsulitis. The patients' range of motion and signs of impingement were documented. The supraspinatus outlet radiographs were assessed, and each patient's acromial morphology was graded as type I, II, or III. A case control group of 53 patients (58 shoulders) was assessed to determine the validity of our results. This group consisted of a series of new patients that were referred to the clinic during February 2003 for assessment of their shoulders. RESULTS: The average age of the patients in the adhesive capsulitis group was 52.5 +/- 7.6 years, with 34 women (50.7%) and 33 men (49.3%). The control group had an average age of 51.1 +/- 16.9 years in a series of 19 (35.8%) women and 34 (64.2%) men. The average range of motion was 98.0 degrees +/- 23.5 degrees of forward elevation, and 91.9 degrees +/- 24.3 degrees of abduction. The forward elevation was 165.5 degrees +/- 15.3 degrees and the abduction was 162.4 degrees +/- 18.4 degrees. The predominant acromial morphology in both groups in this study was a type II acromion (75.4% in the adhesive capsulitis group and 74.1% in the control group). The chi-square analysis within the specific groups showed statistically significant differences in the number of type II compared with type I acromions, and type II compared with type III acromions in both series. However, statistical analysis showed no significant difference between the various acromial types when comparing the adhesive capsulitis group with the control group. CONCLUSIONS: Our results show a significant number of patients with both adhesive capsulitis and, in the control group, type II acromions. We found no statistical difference between these 2 groups. Based on our results, the intrinsic trauma that occurs from subacromial space narrowing caused by the anterior acromial shape, cannot be implicated as the cause of primary adhesive capsulitis. LEVEL OF EVIDENCE: Level III, case control study.

Acromion↗
PubMed2004

Margin convergence of the posterior rotator cuff to the biceps tendon.

Massive rotator cuff tears can often be repaired arthroscopically with satisfactory results. Tear pattern recognition, knot security, and loop security are essential in the repair of large and massive rotator cuff tears. In the case of a massive U-shaped tear, with a contracted immobile supraspinatus and a deficient rotator interval, a type of margin convergence technique can be used. This technique allows for the partial closure of the rotator cuff defect along with the proximal advancement of the posterior cuff by securing the posterior leaf of the cuff tendon to the tendon of the long head of the biceps brachii. Because of the mechanical effect of strain reduction in margin convergence, this procedure decreases the strain at the margin of the posterior cuff, thereby protecting its repair to bone. Our goal with this procedure is not to obtain healing of the cuff to the biceps, but to optimize the conditions for healing of the rotator cuff to bone.

Arthroscopy↗
PubMed2003

Sutures and suture anchors: update 2003.

PURPOSE: The purpose of this study was to evaluate recently introduced sutures and suture anchors for single-pull load-to-failure strength and failure mode. TYPE OF STUDY: Experimental laboratory biomechanical study. METHODS: Using an established protocol in fresh porcine femurs, anchors were tested in diaphyseal cortex, metaphyseal cortex, and cancellous troughs after threading them with either steel sutures or strong synthetic material to reduce the likelihood of suture breakage as a mode of failure. An Instron machine (Instron, Canton, MA) applied tensile loads parallel to the axis of insertion at a rate of 12.5 mm/second until failure, and mean anchor failure strengths were calculated. Mode of failure was recorded (anchor pullout, suture eyelet cutout, or wire breakage). Anchors tested included the RotorloC (Smith & Nephew Endoscopy, Andover, MA), TwinFix Ti 3.5, TwinFix Ti 5.0, and TwinFix AB (Smith & Nephew Endoscopy), Super Revo and UltraSorb (Linvatec, Largo, FL), Duet (Bionx Implants, Blue Bell, PA), AlloAnchor RC (Regeneration Technologies, Alachua, FL), Opus Magnum anchor (Opus Medical, San Juan Capistrano, CA), and the BioCorkscrew 5.0 and BioCorkscrew 6.5 (Arthrex, Naples, FL). Sutures tested were No.2 and No. 5 Ethibond (Ethicon, Somerville, NJ), No. 2 Panacryl (Mitek, a division of Ethicon, Somerville, NJ), and Nos. 2, 5, and 2-0 Fiberwire (Arthrex, Naples, FL). RESULTS: The sutures all broke in the midpoint of their tested strand away from the grips. The No. 2 Ethibond failed at a mean of 21 lb (92 N); No. 5 Ethibond failed at a mean of 44 lb (193 N); No. 2, No. 5, and No. 2-0 Fiberwire at means of 44 lb (188 N), 112 lb (483N), and 19 lb (82 N), respectively; and No. 2 Panacryl at a mean of 22 lb (99 N). The suture anchors all failed at levels higher than the associated sutures. CONCLUSIONS: Screw anchors showed higher load to failure values than nonscrew designs, and the new biodegradable anchors showed failure loads lower than the anchors. All anchors were stronger than the suture for which they are designed.

Animals↗
PubMed2003

Subscapularis tears: arthroscopic repair techniques.

The subscapularis is an essential component of normal shoulder function. An intact subscapularis muscle provides the anterior moment for the transverse plane force couple. Any disruption of the subscapularis disrupts normal glenohumeral biomechanics. If this occurs the shoulder functions abnormally, leading to pain and disability. A thorough history and physical examination lead the surgeon to the diagnosis of a torn subscapularis. Radiographs and MRI are helpful in delineating the rotator cuff tear pattern and other intra-articular lesions and in determining subcoracoid stenosis. Advancements with arthroscopic techniques have enabled surgeons to deal with subscapularis tears arthroscopically. There are seven key points to arthroscopic subscapularis repair: (1) portal placement (posterior portal, anterior portal, anterolateral portal, and accessory anterolateral portal), (2) visualization of the pathology by using a 30 degree and a 70 degree arthroscope, (3) manipulating the arm into maximal internal rotation to assist in assessing the tendon's relationship to its footprint, (4) appropriate anchor placement, (5) suture passage through the tendon, (6) tying secure arthroscopic knots, and (7) appropriate rehabilitation that minimizes stress on the repair. With these principles in mind, the shoulder surgeon can address disruptions of the anterior rotator cuff by repairing the subscapularis, thus alleviating the disability associated with this overlooked and under-appreciated pathology.

Arthroscopy↗
PubMed2003

Iliotibial band Z-lengthening.

Iliotibial band friction syndrome (ITBFS) is a common overuse injury reported to afflict 1.6% to 12% of runners. It results from an inflammatory response secondary to excessive friction that occurs between the lateral femoral epicondyle and the iliotibial band. Initial treatments include rest, anti-inflammatory medication, modalities (ice or heat), stretching, physical therapy, and possibly a cortisone injection. In recalcitrant cases of ITBFS, surgery has been advocated. This report describes a surgical technique of Z-lengthening of the iliotibial band in patients presenting with lateral knee pain localized to the iliotibial band at the lateral femoral epicondyle and Gerdy's tubercle who failed all nonoperative efforts.

Anti-Inflammatory Agents↗
PubMed2002

Relation between ankle joint dynamics and patellar tendinopathy in elite volleyball players.

OBJECTIVE: Ankle joint complex dynamics developed during volleyball spike jumps take-offs and landings were quantified to assess potential relations between these joint dynamics and patellar tendinopathy. DESIGN: Three-dimensional kinematic data provided information about movements of the lower limbs, while the kinetic data permitted analysis of ground reaction forces as players took-off and landed from full-speed spike jumps. SETTING: Simulated volleyball court with net in a biomechanics research laboratory. PARTICIPANTS: 10 members of the Canadian Men's National Volleyball Team. From history and physical examination, 3 of the 10 players had patellar tendon pain associated with activity and were diagnosed with patellar tendinopathy at the time of the study. Investigators were blinded about the injury status of the players. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Three-dimensional kinematics and joint moments of the ankle, knee, and hip joints. RESULTS: Our analysis revealed that maximal external tibial rotation occurred at or near maximal dorsiflexion while maximal internal tibial rotation coincided with maximal plantarflexion. The plantarflexion moment was 3 to 10 times greater than all the other moments measured, with the maximal plantarflexor moment being calculated at 0.4 BWm (360 Nm). In blinded logistic regression analyses, we found one of the dynamics variables (inversion moment during the landing of the spike jump) was a significant predictor of patellar tendinopathy. CONCLUSIONS: Coupling the results of the current analysis of ankle joint complex dynamics with previously reported results of knee joint dynamics related to patellar tendinopathy suggests that a cluster of variables linked to patellar tendinopathy includes: high ankle inversion-eversion moments, high external tibial rotation and plantarflexion moments, large vertical ground reaction forces, and high rate of knee extensor moment development.

Adult↗
PubMedDate not supplied

Repair of quadriceps tendon ruptures using suture anchors.

The repair of ruptured quadriceps tendon is commonly performed by weaving sutures through the ruptured tendon and then attaching the tendon to the bone by passing these sutures through tunnels in the superior patella. This technical note is the first report we are aware of in the English language literature of a technique that uses suture anchors to attach the tendon to bone.

Basketball↗