Effect of ice on pain after corticosteroid injection in the hand and wrist: a randomized controlled trial

This prospective, randomized controlled study was designed to determine if applying ice to the site of corticosteroid injections in the hand and wrist reduces post-injection pain. Patients receiving corticosteroid injections in the hand or wrist at a tertiary institution were enrolled. Subjects were randomized to apply ice to the injection site and take scheduled over-the-counter analgesics ( n = 36) or take scheduled over-the-counter analgesics alone ( n = 32). There were no significant differences in the mean pain score between the two groups at any time-point (pre-injection or 1-5 days post-injection). In regression modelling, the application of ice did not predict pain after injection. Visual analogue pain scores increased at least 2 points (0-10 scale) after injection in 17 out of 36 patients in the ice group versus ten out of 32 control patients. We conclude that the application of ice in addition to over-the-counter analgesics does not reduce post-injection pain after corticosteroid injection in the hand or wrist.

LEVEL OF EVIDENCE

I Therapeutic Study.

The early inflammatory response after flexor tendon healing: a gene expression and histological analysis

Despite advances in surgical techniques over the past three decades, tendon repairs remain prone to poor clinical outcomes. Previous attempts to improve tendon healing have focused on the later stages of healing (i.e., proliferation and matrix synthesis). The early inflammatory phase of tendon healing, however, is not fully understood and its modulation during healing has not yet been studied. Therefore, the purpose of this work was to characterize the early inflammatory phase of flexor tendon healing with the goal of identifying inflammation-related targets for future treatments. Canine flexor tendons were transected and repaired using techniques identical to those used clinically. The inflammatory response was monitored for 9 days. Temporal changes in immune cell populations and gene expression of inflammation-, matrix degradation-, and extracellular matrix-related factors were examined. Gene expression patterns paralleled changes in repair-site cell populations. Of the observed changes, the most dramatic effect was a greater than 4,000-fold up-regulation in the expression of the pro-inflammatory factor IL-1β. While an inflammatory response is likely necessary for healing to occur, high levels of pro-inflammatory cytokines may result in collateral tissue damage and impaired tendon healing. These findings suggest that future tendon treatment approaches consider modulation of the inflammatory phase of healing.

Intrasynovial flexor tendon repair: a biomechanical study of variations in suture application in human cadavera

To improve the functional outcomes of intrasynovial tendon suture, prior experiments evaluated individual technical modifications used in the repair process. Few studies, however, have assessed the combinatorial effects of those suture modifications in an integrated biomechanical manner, including a sample size sufficient to make definitive observations on repair technique. Two hundred fifty-six flexor tendon repairs were performed in human cadavera, and biomechanical properties were determined. The effects of five factors for flexor tendon repair were tested: core suture caliber (4-0 or 3-0), number of sutures crossing the repair site (four- or eight-strand), core suture purchase (0.75 or 1.2 cm), peripheral suture caliber (6-0 or 5-0), and peripheral suture purchase (superficial or 2 mm). Significant factors affecting the properties of the repair were the number of core suture strands and the peripheral suture purchase. The least significant factors were core suture purchase and peripheral suture caliber. The choice of core suture caliber affected the properties of repair marginally. Based on these results, we recommend that surgeons continue to focus on multi-strand repair methods, as the properties of eight-strand repairs were far better than those of four-strand repairs. To resist gap formation and enhance repair strength, a peripheral suture with 2 mm purchase is also recommended. Finally, since core suture caliber affected some biomechanical properties, including the failure mode, a 3-0 suture could be considered, provided that future in vivo studies can confirm that gliding properties are not adversely influenced.

Enhanced flexor tendon healing through controlled delivery of PDGF-BB

A fibrin/heparin-based delivery system was used to provide controlled delivery of platelet derived growth factor BB (PDGF-BB) in an animal model of intrasynovial flexor tendon repair. We hypothesized that PDGF-BB, administered in this manner, would stimulate cell proliferation and matrix remodeling, leading to improvements in the sutured tendon's functional and structural properties. Fifty-six flexor digitorum profundus tendons were injured and repaired in 28 dogs. Three groups were compared: (1) controlled delivery of PDGF-BB using a fibrin/heparin-based delivery system; (2) delivery system carrier control; and (3) repair- only control. The operated forelimbs were treated with controlled passive motion rehabilitation. The animals were euthanized at 7, 14, and 42 days, at which time the tendons were assessed using histologic (hyaluronic acid content, cellularity, and inflammation), biochemical (total DNA and reducible collagen crosslink levels), and biomechanical (gliding and tensile properties) assays. We found that cell activity (as determined by total DNA, collagen crosslink analyses, and hyaluronic acid content) was accelerated due to PDGF-BB at 14 days. Proximal interphalangeal joint rotation and tendon excursion (i.e., tendon gliding properties) were significantly higher for the PDGF-BB-treated tendons compared to the repair-alone tendons at 42 days. Improvements in tensile properties were not achieved, possibly due to suboptimal release kinetics or other factors. In conclusion, PDGF-BB treatment consistently improved the functional but not the structural properties of sutured intrasynovial tendons through 42 days following repair.

Supplementary core sutures increase resistance to gapping for flexor digitorum profundus tendon to bone surface repair - an in vitro biomechanical analysis

We evaluated the effects of two types of supplementary core sutures on the tensile properties and resistance to gap formation of flexor digitorum profundus (FDP) tendon-bone repairs. Forty-five human cadaver FDP tendons were sharply released from their insertion sites and repaired to bone utilizing one of three repair techniques: four-strand modified Becker core suture (Becker only), modified Becker plus a figure-of-eight supplementary core suture (Becker plus figure-of-eight), and modified Becker plus a supplementary core suture using a bone anchor (Becker plus anchor). Ultimate (maximum) force did not differ between repair groups. However, addition of a supplementary suture significantly increased repair-site stiffness and the 1, 2 and 3 mm gap forces, while decreasing the gap at 20 N compared to the Becker only suture (P<0.05). The only difference between the two supplementary suture groups was that the Becker plus anchor group had increased stiffness compared to the Becker plus figure-of-eight group. In conclusion, a supplementary figure-of-eight suture and a supplementary suture using a bone anchor provide enhanced resistance to gap formation for FDP tendon-bone repairs.

The influence of cross-sectional area on the tensile properties of flexor tendons

Clinicians have long noted substantial variation in the cross-sectional size of flexor tendons in the hand; however, data indicating that surgical repair techniques of lacerated flexor tendons should be altered according to size are unavailable. Our objectives were to evaluate the cross-sectional size differences among tendons within the same hand and to correlate tendon size with tensile mechanical properties after suture repair. Fifty human cadaver flexor digitorum profundus tendons were measured with digital calipers to determine radioulnar and volardorsal diameters. Twenty tendons were used to measure resistance to suture pull-through; tendons were transected at the A2 pulley, and a transverse double-stranded 4-0 Supramid suture (S. Jackson, Inc, Alexandria, VA) was passed through the radioulnar plane of the tendon 1 cm from the transection site. The remaining tendons were transected and repaired by using a modified Kessler repair with double-stranded 4-0 Supramid suture. Both tendon repairs and tendon-suture pull-through specimens were tested to failure in tension by using a material testing machine. Dorsovolar tendon height and tendon cross-sectional area varied significantly between digits, with an average difference of approximately 40% between the values of the smallest (fifth) and largest (third) fingers. Yield and ultimate force determined by pull-through tests of the simple transverse suture correlated positively with tendon radioulnar width. Tensile properties of tendons repaired with a double-stranded modified Kessler repair, however, did not depend significantly on tendon size. These results indicate that the strength of the commonly used Kessler suture technique is not dependent on tendon cross-sectional size within the clinically relevant range of tendons evaluated.

Quantitative variation in vascular endothelial growth factor mRNA expression during early flexor tendon healing: an investigation in a canine model

Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis, with direct mitogenic activity on cells of endothelial origin. We quantified the temporal accumulation of VEGF mRNA at the repair site of an in vivo canine intrasynovial flexor tendon repair and rehabilitation model by means of quantitative Northern blot analysis, in order to detail a molecular signal involved in the intrinsic angiogenic process that accompanies early flexor tendon healing. Significant accumulation of VEGF mRNA occurred at the flexor tendon repair site at 7 days post-operatively, with peak levels seen at post-operative days 7 and 10. Levels returned to baseline by day 14. Local VEGF mRNA accumulation at the repair site temporally precedes and is spatially distinct from the vascular ingrowth itself, which has been shown to occur maximally at day 17. These data suggest that cells within the flexor tendon repair site are involved in molecular processes other than the synthesis of extracellular matrix, such as modulation of angiogenesis.

The effect of variations in applied rehabilitation force on collagen concentration and maturation at the intrasynovial flexor tendon repair site

The biochemical means by which accelerated rehabilitation alters intrasynovial flexor tendon repair site collagen synthesis and extracellular matrix maturation are not fully understood. We hypothesized that an increased level of applied rehabilitative force in a clinically relevant animal model would hasten the maturation of the repair site extracellular matrix as demonstrated by total collagen and collagen cross-link assessment. Twenty-eight flexor digitorum profundus tendons from 14 adult dogs were transected and repaired. The animals received either low- or high-force rehabilitation and were killed 10, 21, and 42 days after surgery. A 10-mm segment of tendon surrounding the repair site was obtained. Biochemical analysis showed that total collagen concentration was significantly reduced at each time point, that the reducible cross-link ratio of dihydroxylysinonorleucine to hydroxylysinonorleucine was significantly increased at each time point, and that the nonreducible pyridinoline cross-link content was significantly decreased at 10 days in both rehabilitative groups. Total collagen content did not vary to a statistically significant degree with either time or as a function of rehabilitation type. Based on these findings several clinically relevant observations can be made. Increasing collagen concentration and repair site maturation do not explain the previously demonstrated increased tensile properties of tendon that occur between 3 and 6 weeks after repair. Higher force rehabilitation does not alter the biochemical composition of the healing tendon through 6 weeks. Coupled with other recent data these findings suggest that high-force rehabilitation does not stimulate accelerated healing after intrasynovial flexor tendon repair.

Intrasynovial flexor tendon repair. An experimental study comparing low and high levels of in vivo force during rehabilitation in canines

BACKGROUND

Rehabilitation methods that generate increased tendon force and motion have been advocated to improve results following intrasynovial flexor tendon repair. However, the effects of rehabilitation force and motion on tendon-healing may be masked by the high stiffness produced by newer suture methods. Our objective was to determine whether the biomechanical properties of tendons repaired by one of two multistrand suture methods were sensitive to an increased level of applied rehabilitation force.

METHODS

Two hundred and fourteen flexor digitorum profundus tendons from 107 adult dogs were transected and repaired. Dogs were assigned to one of four groups based on the rehabilitation method (low force [<5 N] or high force [17 N]) and the repair technique (four-strand or eight-strand core suture) and were killed between five and forty-two days after the procedure. Repair-site structural properties were determined by tensile testing, and digital range of motion was assessed with use of a motion-analysis system.

RESULTS

Tensile properties did not differ between the low and high-force rehabilitation groups, regardless of the repair technique (p > 0.05). In contrast, tensile properties were strongly affected by the repair technique, with tendons in the eight-strand group having an approximately 35% increase in ultimate force and rigidity compared with those in the four-strand group (p < 0.05). Ultimate force did not change significantly with time during the first twenty-one days (p > 0.05); there was no evidence of softening in either of the repair or rehabilitation groups. Force increased significantly from twenty-one to forty-two days, while rigidity increased throughout the forty-two-day period (p < 0.05).

CONCLUSIONS

Increasing the level of force applied during postoperative rehabilitation from 5 to 17 N did not accelerate the time-dependent accrual of stiffness or strength. Suture technique was of primary importance in providing a stiff and strong repair throughout the early healing interval.

CLINICAL RELEVANCE

Our findings suggest that there be a reexamination of the concept that increases in force produced by more vigorous mobilization protocols are beneficial to tendon-healing. While more vigorous rehabilitation may help to improve hand function, we found no evidence that it enhances tissue-healing or strength in the context of a modern suture repair.

Suture methods for flexor tendon repair. A biomechanical analysis during the first six weeks following repair

This review describes the evolution of recently developed multi-strand, multi-grasp flexor tendon suture techniques. Analyses of digital angular joint rotation, tendon excursion, and ultimate tensile load at the time of repair and at three and six weeks following repair allowed comparison of a variety of innovative grasping and non-grasping multi-strand techniques. The first series of experiments describes an analysis of the Tajima, Tsuge, Savage, Kessler, double loop locking suture, and recently developed eight-strand suture techniques at the time of repair. The Tajima, Savage, and eight-strand repair methods were found to have statistically significant improved gliding function compared to those methods that featured external knots (Kessler and Tsuge) and methods that tended to bunch at the repair site (double loop locking suture). With regard to ultimate tensile load, the eight-strand repair was found to have the greatest strength (69N) of all tested methods (p < 0.05). The second series of experiments examined the Tajima, Kessler, Savage, and eight-strand suture methods at three and six weeks following tendon repair. A high percentage of failure within the Kessler repairs precluded their inclusion for final comparative analysis. The results for the remaining three techniques were normalized (experimental/control) to allow inter-group comparison. For intrasynovial tendon repair gliding function, all prepared specimens were found to have significantly less tendon excursion, proximal interphalangeal joint rotation, and distal interphalangeal joint rotation than their respective controls. However, no statistical differences were noted in gliding function between the Tajima, Savage, and eight-strand repair at three and six weeks (p < 0.05). Ultimate tensile testing ascertained that the eight strand method demonstrated significantly greater strength at three (52.6N) and six (70.9N) weeks than both the Tajima and Savage techniques (p < 0.05), while the Savage repair had significantly greater strength than the Tajima repair (p < 0.05). On the basis of these findings, we suggest that early controlled active motion protocols be devised using the multi-strand multi-grasp techniques, as exemplified by the eight strand tendon repair method, in an effort to achieve consistently improved results for intrasynovial flexor tendon repairs.

Integrin expression is upregulated during early healing in a canine intrasynovial flexor tendon repair and controlled passive motion model

To explore crucial early molecular events involved in contact healing of the intrasynovial flexor tendon, integrin expression was evaluated at the transcriptional and post-transcriptional levels during the first two weeks following injury, repair and controlled passive motion in a canine model. Specifically, immunohistochemical and reverse transcription polymerase chain reaction (RT-PCR) techniques were employed to evaluate expression of the fibronectin, vitronectin and endothelial cell binding integrin receptor subunits alpha5, alphav and alpha6, along with the common beta1 subunit. The two techniques revealed increasing expression of the four subunits over the two week post-repair period. Immunohistochemistry revealed that beta1 and alpha5 expression was concentrated in the epitenon layer near the repair site and interiorly within the wound area, while alpha6 was associated with capillary-forming endothelial cells near the wound. RT-PCR and quantitation by NIH image analysis demonstrated peak messenger RNA expression of beta1 and alpha5 at ten days post-repair and peak expression of alpha6 and alphav at 15 days. The results in this study correlate well with previous results demonstrating increased fibronectin deposition and angiogenesis during the same time period in a similar injury/repair model.

Vascularity of the carpus

Relatively few studies investigating the vascular patterns of the carpus have been performed. Technical difficulties in identifying small vessels in three dimensions and in determining their location within the thick ligaments about the wrist have led to conflicting anatomic reports. Studies on cadavers in which improved techniques with arterial injection, chemical debridement, and decalcification were used allowed the arterial anatomy of the carpus to be delineated more accurately. The current authors review these arterial patterns, with attention given to the extraosseous and intraosseous vascularities.

Arterial patterns of the deep and superficial palmar arches

The vascular patterns of the palmar arches and their interconnecting branches present a complex and challenging area of study. Improvements in microsurgical techniques have made a better understanding of vascular patterns and vessel diameters more important. Forty-five fresh limbs from cadavers were amputated at the level of the midhumerus. Ward's red latex or Batson's compound was injected under pressure to visualize the arterial system in the hand. After hardening of the injected material, the skin, subcutaneous tissues, and tendons were removed. The specimens were digested in concentrated potassium or sodium hydroxide leaving the bony elements and a cast of the arterial system. The superficial palmar arch is most easily classified into two categories: complete or incomplete. An arch is considered to be complete if an anastomosis is found between the vessels constituting it. An incomplete arch has an absence of a communication or anastomosis between the vessels constituting the arch. Complete superficial palmar arches were seen in 84.4% of specimens. In the most common type, the superficial arch was formed by anastomosis between the superficial volar branch of the radial artery and the ulnar artery. This was seen in 35.5% of specimens. In 31.1%, the arch was formed entirely of the ulnar artery. Incomplete superficial arches were seen in 15.5% of specimens. In 11.1%, the ulnar artery forms the superficial arch but does not contribute to the blood supply to the thumb and index finger. The deep palmar arch was found to be less variable with 44.4% formed by an anastomosis between the deep volar branch of the radial artery and the inferior deep branch of the ulnar artery. Injection followed by chemical debridement allows direct visualization and measurement of the arches and the smaller arterial branches that are visualized poorly with other techniques. Based on the vessel measured, vessels of the superficial and deep arches are of sufficient size to allow microvascular repair, although repair of the communicating branches, the dorsal carpal rete, and its branches, probably is not feasible because of their small size.

Capitolunate arthrodesis with scaphoid and triquetrum excision

A retrospective two-center outcome study was designed to evaluate the results of capitolunate arthrodesis with scaphoid and triquetrum excision mainly for scapholunate advanced collapse patterns of arthritis. Fourteen wrists in 14 patients were evaluated objectively by standard parameters and subjectively by the Short Musculoskeletal Functional Assessment at an average of 28 months after surgery (range, 14-51 months). All patients were men between the ages of 20 and 70 years (average, 49 years). Two patients had a painful nonunion and one had persistent pain despite conversion to a solid wrist arthrodesis. One patient had x-ray evidence of progressive radiolunate narrowing, but only occasional pain. Postoperative wrist flexion-extension arc was 53 degrees and radioulnar deviation arc was 18 degrees. Grip and pinch strengths were 71% and 75%, respectively, of the normal contralateral wrist. The results of our study indicate that capitolunate arthrodesis with scaphoid and triquetrum excision is comparable to other motion-preserving operative procedures for scapholunate advance collapse.

Flexor tendon grafting to the hand: an assessment of the intrasynovial donor tendon-A preliminary single-cohort study

We report the results of a pilot study using intrasynovial donor tendons for flexor tendon reconstruction in 8 patients (10 digits) at a mean follow-up time of 3.8 years for neglected or failed primary repair of zone 2 lacerations and for neglected flexor digitorum profundus avulsions. The flexor digitorum longus to the second toe was used as the donor tendon graft. Four patients (4 digits) underwent single-stage reconstruction and 4 patients (6 digits) had multistage reconstruction. The overall patient satisfaction using a standardized visual analog reporting scale was excellent. There was 1 excellent, 1 good, 1 fair, and 1 poor result in the single-stage reconstruction group, including 1 repair site rupture and 1 digit requiring tenolysis. In the multistage reconstruction group there was 1 excellent, 3 good, 1 fair, and no poor results, including 1 digit requiring tenolysis. One patient was lost to follow-up. There was no donor site morbidity. The average active motion recovery was 64% and 56% for single-stage and multistage reconstructions, respectively, and was 73% overall for single digit reconstructions. The results of this pilot study suggest that intrasynovial tendon grafting may offer an improved alternative for tendon grafting to the synovial spaces of the digit.

The resistance of a four- and eight-strand suture technique to gap formation during tensile testing: an experimental study of repaired canine flexor tendons after 10 days of in vivo healing

There is a high incidence of gap formation at the repair site following tendon repair. Our goal was to determine the resistance of a 4- and an 8-strand suture technique to gap formation during tensile testing. We hypothesized that the 8-strand repair would sustain higher force levels at the onset of 1- and 3-mm gaps than the 4- strand repair. Twenty-two canine flexor tendons were transected, repaired, and tested to failure after 10 days of in vivo healing. Tests were recorded using a 60-Hz video system that allowed frame-by-frame playback for assessment of gap formation. The 8-strand repairs sustained 80% higher force at a gap of 1 mm than the 4-strand repairs (average force, 70 vs 39 N), but the force sustained at a gap of 3 mm did not differ between groups (35 N for both groups). For both repair types, a 1-mm gap typically occurred near the point of ultimate (maximum) force while a 3-mm gap occurred after the ultimate force. We conclude that the 8-strand repair is significantly more resistant to initial gapping during ex vivo tensile testing than the 4-strand repair but that the two repairs are equally susceptible to rupture if a gap of 3 mm or greater forms.

Expression of mRNA for vascular endothelial growth factor at the repair site of healing canine flexor tendon

Neovascularization is an important and prominent feature of tendon healing that contributes to wound repair and potentially to adhesion formation. To define the location of cell populations that recruit and organize the angiogenic response during early healing of flexor tendon, we examined the gene expression pattern of the prototypic angiogenic factor, vascular endothelial growth factor, at and around the tenorrhaphy site in a canine model of flexor tendon repair. In situ hybridization with radiolabeled antisense riboprobes was used to identify tendon cell populations that contribute to the neovascularization process by expressing vascular endothelial growth factor and to relate this cell population to the previously described cell populations that participate in matrix synthesis (express type alpha1(I) collagen) and mitotic renewal (express histone H4). The majority of cells (approximately 67%) within the repair site itself express vascular endothelial growth factor mRNA; however, minimal levels accumulate within cells of the epitenon (approximately 10% of cells; p < 0.0002). By contrast, expression of type alpha1(I) collagen and histone H4 does not differ significantly between the epitenon and the repair site (uniformly approximately 30% of cells). Thus, a gradient of cell populations expressing vascular endothelial growth factor exists in the repairing tendon. These data suggest a potential contribution of cells within the repair site to the organization of angiogenesis during the early postoperative phase of tendon healing.

Regulation of alpha(v)beta3 and alpha5beta1 integrin receptors by basic fibroblast growth factor and platelet-derived growth factor-BB in intrasynovial flexor tendon cells

Integrins are important players in soft tissue healing as molecules that mediate communication between cells and extracellular matrix. Thus, the regulation of the expression of these molecules would be important during wound repair. To explore the regulatory roles of specific growth factors on integrin expression by intrasynovial flexor tendon cells, the present study assessed the in vitro effects of basic fibroblast growth factor and platelet derived growth factor-BB on expression of the alpha5beta1 and alpha(v)beta3 integrins in these cells. Analyses were carried out at the transcriptional (reverse transcription-polymerase chain reaction) and translational (immunohistochemistry) levels of cellular metabolism. Both types of analyses revealed increased expression of alpha5beta1 and alpha(v)beta3 by tendon cells exposed to either basic fibroblast growth factor or platelet-derived growth factor-BB over a wide range of growth factor concentrations employed in the study. Semiquantitative reverse transcription-polymerase chain reaction showed that, relative to control, basic fibroblast growth factor and platelet-derived growth factor-BB increased the expression of alpha(v) mRNA by 2-and 3-fold, respectively. Alpha 5 mRNA expression was also increased 3-fold by basic fibroblast growth factor, and 2-fold by platelet-derived growth factor-BB. We believe the results of this study are significant because the specific integrins affected are intimately involved in two events that have been shown to be important to intrasynovial flexor tendon healing, namely fibronectin deposition (alpha5beta1) as part of the provisional matrix and angiogenesis/revascularization (alpha(v)beta3).

Effects of increased in vivo excursion on digital range of motion and tendon strength following flexor tendon repair

Postoperative rehabilitation is an important factor in determining functional outcome following intrasynovial flexor tendon repair. We hypothesized that a rehabilitation protocol that produced increased in vivo excursion would lead to increased digital range of motion and tendon strength and decreased adhesion formation in a canine model. Ninety-six flexor digitorum profundus tendons from 48 dogs were cut transversely and repaired by a multistrand suture technique. Postoperative rehabilitation was performed daily with a low excursion-low force (1.7-mm average excursion; < 10 N force) or a high excursion-low force (3.6 mm excursion; < 10 N force) protocol. After death of the dogs at 10, 21, or 42 days, specimens were evaluated for digital range of motion, tensile mechanical properties, elongation of the repair site, and adhesion formation. Our data indicate that the range of motion of digits whose tendons were at low or high excursion was similar to that of controls. Increased in vivo tendon excursion due to synergistic wrist motion did not significantly affect ex vivo flexion of the distal and proximal interphalangeal joints or tendon displacement (p > 0.05). Similarly, tensile properties (ultimate load, repair site rigidity, and repair site strain at 20 N and at failure) and length of the gap at the repair site were not significantly affected by increased excursion (p > 0.05). Severity of adhesion formation was reduced slightly by increased excursion (p = 0.04). Our findings indicate that 1.7 mm of tendon excursion is sufficient to prevent adhesion formation following sharp transection of the canine flexor tendon and that additional excursion provides little added benefit.

The effect of gap formation at the repair site on the strength and excursion of intrasynovial flexor tendons. An experimental study on the early stages of tendon-healing in dogs

BACKGROUND

Elongation (gap formation) at the repair site has been associated with the formation of adhesions and a poor functional outcome after repair of flexor tendons. Our objectives were to evaluate the prevalence of gap formation in a clinically relevant canine model and to assess the effect of gap size on the range of motion of the digits and the mechanical properties of the tendons.

METHODS

We performed operative repairs after sharp transection of sixty-four flexor tendons in thirty-two adult dogs. Rehabilitation with passive motion was performed daily until the dogs were killed at ten, twenty-one, or forty-two days postoperatively. Eight tendons ruptured in vivo. In the fifty-six intact specimens, the change in the angles of the proximal and distal interphalangeal joints and the linear excursion of the flexor tendon were measured as a 1.5-newton force was applied to the tendon. The gap at the repair site was then measured, and the isolated tendons were tested to failure in tension.

RESULTS

Twenty-nine tendons had a gap of less than one millimeter, twelve had a gap of one to three millimeters, and fifteen had a gap of more than three millimeters. Neither the time after the repair nor the size of the gap was found to have a significant effect on motion parameters (p > 0.05); however, the ultimate force, repair-site rigidity, and repair-site strain at twenty newtons were significantly affected by these parameters (p < 0.05). Testing of the tendons with a gap of three millimeters or less revealed that, compared with the ten-day specimens, the forty-two-day specimens failed at a significantly (90 percent) higher force (p < 0.01) and had a significantly (320 percent) increased rigidity (p < 0.01) and a significantly (60 percent) decreased strain at twenty newtons (p < 0.05). In contrast, the tensile properties of the tendons that had a gap of more than three millimeters did not change significantly with time.

CONCLUSIONS

Our data indicate that, in a dog model involving sharp transection followed by repair, a gap at the repair site of more than three millimeters does not increase the prevalence of adhesions or impair the range of motion but does prevent the accrual of strength and stiffness that normally occurs with time.

Operative correction of swan-neck and boutonniere deformities in the rheumatoid hand

A swan-neck or boutonniere deformity occurs in approximately half of patients with rheumatoid arthritis. The cause of boutonniere deformity is chronic synovitis of the proximal interphalangeal joint. Swan-neck deformity may be caused by synovitis of the metacarpophalangeal, proximal interphalangeal, or distal interphalangeal joints. Numerous procedures are available for the operative correction of these finger deformities. The choice of surgical procedure is dependent on accurate staging of the deformity, which is based on the flexibility of the proximal interphalangeal joint and the state of the articular cartilage. The patient's overall medical status and corticosteroid use, the condition of the cervical spine, the need for operative treatment of large joints, and the presence of deformities of the wrist and metacarpophalangeal joints must also be considered when planning treatment. In the later stages of both deformities, soft-tissue procedures alone may not result in lasting operative correction.

Wrist and digital joint motion produce unique flexor tendon force and excursion in the canine forelimb

The force and excursion within the canine digital flexor tendons were measured during passive joint manipulations that simulate those used during rehabilitation after flexor tendon repair and during active muscle contraction, simulating the active rehabilitation protocol. Tendon force was measured using a small buckle placed upon the tendon while excursion was measured using a suture marker and video analysis method. Passive finger motion imposed with the wrist flexed resulted in dramatically lower tendon force (approximately 5 N) compared to passive motion imposed with the wrist extended (approximately 17 N). Lower excursions were seen at the level of the proximal interphalangeal joint with the wrist flexed (approximately 1.5 mm) while high excursion was observed when the wrist was extended or when synergistic finger and wrist motion were imposed (approximately 3.5 mm). Bivariate discriminant analysis of both force and excursion data revealed a natural clustering of the data into three general mechanical paradigms. With the wrist extended and with either one finger or four fingers manipulated, tendons experienced high loads of approximately 1500 g and high excursions of approximately 3.5 mm. In contrast, the same manipulations performed with the wrist flexed resulted in low tendon forces (4-8 N) and low tendon excursions of approximately 1.5 mm. Synergistic wrist and finger manipulation provided the third paradigm where tendon force was relatively low (approximately 4 N) but excursion was as high as those seen in the groups which were manipulated with the wrist extended. Active muscle contraction produced a modest tendon excursion (approximately 1 mm) and high or low tendon force with the wrist extended or flexed, respectively. These data provide the basis for experimentally testable hypotheses with regard to the factors that most significantly affect functional recovery after digital flexor tendon injury and define the normal mechanical operating characteristics of these tendons.

The effect of dorsal carpal ganglion excision on the scaphoid shift test

A clinical and radiographic review was performed on 18 patients (19 wrists) with dorsal carpal ganglia and associated positive scaphoid shift test. All patients underwent excision of the ganglion followed by 2 weeks of postoperative immobilization with the wrist in 20 degrees extension. All patients had wrist pain, a painful clunk on the Watson scaphoid shift test, localized tenderness on palpation of the scapholunate articulation and normal radiographs. Patients were assessed postoperatively by questionnaire and physical examination. Improved functional activity and decreased pain were noted in all patients. In 17 of 19 wrists, the positive preoperative Watson scaphoid shift test become negative. We believe that dorsal wrist ganglia are frequently associated with a positive scaphoid shift test and that excision of the ganglion followed by 2 weeks immobilization may lead to resolution of the signs and symptoms of instability, at least in the short term.

Complications of the operative treatment of Dupuytren's disease

Complications of surgery for Dupuytren's disease occur intra-operatively as well as during the early and late postoperative periods. Digital nerve injury, vascular injury, skin flap "button holes," hematoma, swelling, infection, flare, wound dehiscence, recurrence, pseudoaneurysm, and inclusion cysts are discussed and their treatment reviewed. Recognition of the complication is necessary for motion therapy to proceed in a timely fashion in order to avoid postoperative digital stiffness.

The extraneural and intraneural arterial anatomy of the ulnar nerve at the elbow

The purpose of this report was to investigate the vascular anatomy of the ulnar nerve at the elbow with a technique of combined India ink and latex injection followed by nondissection chemical debridement. Twenty-two fresh human cadaveric arms were injected with India ink to stain the intraneural microcirculation followed immediately by latex injection and chemical debridement for study of the extraneural vascularization. After clearing with a modified Spalteholtz technique, the intraneural blood supply was studied in 10 of the specimens. The findings demonstrated a consistent but segmental extraneural and intraneural vascular supply from the superior ulnar collateral, inferior ulnar collateral, and posterior ulnar recurrent arteries. No identifiable direct anastomosis was seen between the superior ulnar collateral and posterior ulnar recurrent arteries in 20 of 22 arms. The inferior ulnar collateral artery provided the only direct vascularization to the nerve in the region just proximal to the cubital tunnel. Although the clinical importance of maintaining specific arterial sources to the ulnar nerve has not been determined, these anatomic findings indicate that the arterial contribution from the inferior ulnar collateral artery may be more important than appreciated previously.

The effects of multiple-strand suture techniques on the tensile properties of repair of the flexor digitorum profundus tendon to bone

We examined the effects of multiple-strand suture techniques on the tensile properties of flexor digitorum profundus tendon-to-bone repairs in a human cadaver finger model. Forty-four fingers were obtained from the cadavera of fifteen donors who had been an average of seventy-four years old (range, fifty-four to eighty-nine years old) at the time of death. Four or eight-strand proximal grasping sutures were secured to the distal phalanx of each finger with use of either a suture anchor or a dorsally placed button. There were four subgroups of eleven fingers each. We found that repairs performed with use of a dorsally placed button had greater yield force, ultimate force, and rigidity than those performed with use of an anchor and that repairs performed with eight strands had greater ultimate force than those performed with four strands. These differences were significant (p < 0.05). We could detect no differences among the four types of repairs with regard to the amount of relative tendon-bone elongation at twenty newtons of force. The repairs performed with eight strands and a dorsally placed button had an average yield force (and 95 per cent confidence interval) of 50.0 +/- 14.1 newtons, an average ultimate force of 68.5 +/- 14.6 newtons, an average rigidity of 744 +/- 327 newton/(millimeter/millimeter), and an average tendon-bone elongation of 3.4 +/- 0.7 millimeters at twenty newtons of force. Multiple-comparison testing showed that the eight-strand repairs performed with a dorsally placed button had greater ultimate force than the other three types of repairs as well as greater yield force and rigidity than the four and eight-strand repairs performed with a suture anchor.

Acute compartment syndrome of the forearm

The forearm is the most common site for compartment syndrome in the upper extremity. The three compartments of the forearm include the volar (anterior or flexor), the dorsal (posterior or extensor), and the mobile wad. Both-bone forearm fractures and distal radius fractures are common initial injuries in adults that lead to acute forearm compartment syndrome. Supracondylar fractures, especially those with associated vascular injuries, are frequent causes of compartment syndrome in children. The flexor digitorum profundus and flexor pollicis longus are among the most severely affected muscles because of their deep location, adjacent to bone. Initial treatment consists of removal of occlusive dressings or splitting or removal of casts. If symptoms do not resolve rapidly, fasciotomy is indicated. Decompression fasciotomy of the forearm is performed through volar or dorsal approaches. The medial nerve is decompressed throughout its course, including high-risk areas deep to the lacertus fibrosus; between the humeral and ulnar heads of the pronator teres, the proximal arch, and deep fascial surface of the flexor digitorum superficialis; and the carpal tunnel.

Volkmann's ischemic contracture of the upper extremity

Upper extremity deformity of ischemic contracture usually includes elbow flexion, forearm pronation, wrist flexion, thumb flexion and adduction, digital metacarpophalangeal joint extension, and interphalangeal joint flexion. Treatment of mild contractures consists of either nonoperative management with a comprehensive rehabilitation program (to increase range of motion and strenght) or operative management consisting of infarct excision or tendon lengthening. Treatment of moderate-to-severe contractures consists of release of secondary nerve compression, treatment of contractures (with tendon lengthening or recession), tendon or free-tissue transfers to restore lost function, and/or salvage procedures for the severely contracted or neglected extremity.

Morphologic changes in the ulnar nerve at the elbow with flexion and extension: a magnetic resonance imaging study with 3-dimensional reconstruction

We evaluated the morphology of the ulnar nerve and cubital tunnel with noninvasive magnetic resonance imaging (MRI). We used fresh human cadavers with the elbow in full extension, 90 degrees of flexion, and full flexion. For each elbow, 1-mm slices were imaged interpolated, and reconstructed into 3-dimensional data volumes, and then manually segmented before they were examined with sequential transverse sections, curved sections, and 3-dimensional images. The ulnar nerve follows a tortuous course in full extension, becomes progressively linear with incremental elbow flexion, shifts anteriorly in the cubital tunnel, and flattens against the medial epicondyle. The proximal and midportions of the cubital tunnel also change with flexion from round to elliptical. In addition, successive increases occur in the cross-sectional diameter of the mediolateral plane. The nerve is surrounded by fat throughout the cubital tunnel except adjacent to the medial epicondyle. These observations suggest that the ulnar nerve progressively stretch over the medial epicondyle occurs when the normal elbow is flexed. Direct compression areas of the ulnar nerve were not seen in our study of normal human elbows.

Rehabilitation after subcutaneous transposition of the ulnar nerve: immediate versus delayed mobilization

We studied 36 patients who had clinical signs and symptoms consistent with cubital tunnel syndrome and in whom nonoperative management failed. These patients underwent anterior subcutaneous transposition of the ulnar nerve followed by either immediate (20 patients) or delayed (16 patients) mobilization. All patients were evaluated with an outcomes assessment questionnaire, and 35 of the 36 were given repeat physical examinations. After surgery, there were no significant differences between the two groups in pain relief, weakness, or patient satisfaction (71% of the immediate mobilization group and 74% of the delayed group) were satisfied. Secondary quantitative outcomes such as grip strength, lateral pinch, or two-point discrimination were also not significantly different between the groups. Both groups had a statistically significant improvement in first dorsal interosseous and adductor pollicis muscle strength. In the immediate mobilization group, however, patients returned to work and resumed activities of daily living earlier (median 1 month) than patients in the delayed mobilization group (median 2.75 months). Therefore, we conclude that anterior subcutaneous transposition provides a high degree of satisfaction and relief of symptoms regardless of when mobilization is initiated. However, immediately mobilizing the patient significantly influenced how early the patient returned to work and resumed activities of daily living.

Reconstruction of the flexor pulley. The effect of the tension and source of the graft in an in vitro dog model

Flexor pulleys in the hindpaw digits of twenty-eight adult mixed-breed dogs were reconstructed in order to investigate the influence, on the reconstruction, of the source of the autogenous tissue (intrasynovial compared with extrasynovial tendon) and the tension applied during the repair. The ipsilateral peroneus longus tendon was used to reconstruct the A2 pulley with an around-the-bone technique in twenty-one digits; the graft was sutured at a tension of 0.49, 0.98, and 1.96 newtons in seven digits each. The flexor digitorum profundus tendon of an adjacent digit was used to reconstruct the A2 pulley, at a tension of 0.98 newton, in seven additional digits. The contralateral digits were used as controls for all twenty-eight treated digits. The digits were tested in a custom apparatus designed to measure the frictional force generated between the reconstructed pulley and the tendon beneath it. The frictional force did not differ significantly (p > 0.5) among the three groups repaired with peroneus longus tendon; however, the average value was more than five times that produced in the contralateral, control digits. The average frictional forces created by the flexor digitorum profundus grafts were similar to those in the contralateral, control digits. Reconstruction with the flexor digitorum profundus at a tension of 0.98 newton produced significantly less frictional force (p < 0.05) than that produced by the peroneus longus graft at the same tension. This in vitro model of reconstruction of the A2 pulley demonstrated that tendon from an intrasynovial source (the flexor digitorum profundus) produced less frictional resistance to gliding of the tendon than did tendon from an extrasynovial source (the peroneus longus). This result is consistent with previously published findings that intrasynovial tendons may make better grafts than extrasynovial tendons for the reconstruction of gliding flexor tendons because of decreased friction and better healing qualities. Intrasynovial tendons may also make better grafts for the reconstruction of flexor pulleys.

A new provocative test for carpal tunnel syndrome. Assessment of wrist flexion and nerve compression

To establish the value of median nerve compression with wrist flexion as a provocative test for carpal tunnel syndrome (CTS), we performed a prospective study of 64 patients (95 hands) with CTS confirmed by electrodiagnostic studies and 50 normal subjects (96 hands). We recorded results for the common provocative tests (Tinel's percussion test, Phalen's wrist flexion test and the carpal compression test) and the new test which combines wrist flexion with median nerve compression. Using a receiver operator characteristic curve (ROC) technique, we found that the optimal cut-off time for the wrist-flexion and median-nerve compression test was 20 s, giving a sensitivity of 82% and a specificity of 99%. These results were significantly better than for Phalen's wrist flexion test (61% and 83%, respectively) and for the sensitivity of Tinel's test (74%). The positive predictive values of the wrist flexion and median-nerve compression test, which is more important clinically, were 99%, 95% and 81% at population prevalences of 50%, 20% and 5%, respectively. These were significantly better than those of the three other provocative tests at each prevalence. Electrodiagnostic studies have significant false-positive and false-negative rates in CTS, and therefore provocative tests remain important in its diagnosis. We have shown that wrist flexion combined with the median-nerve compression test at 20 s, is significantly better than the other methods, and may thus be clinically useful.

A new provocative test for carpal tunnel syndrome

To establish the value of median nerve compression with wrist flexion as a provocative test for carpal tunnel syndrome (CTS), we performed a prospective study of 64 patients (95 hands) with CTS confirmed by electrodiagnostic studies and 50 normal subjects (96 hands). We recorded results for the common provocative tests (Tinel’s percussion test, Phalen’s wrist flexion test and the carpal compression test) and the new test which combines wrist flexion with median nerve compression.

Using a receiver operator characteristic curve (ROC) technique, we found that the optimal cut-off time for the wrist-flexion and median-nerve compression test was 20 s, giving a sensitivity of 82% and a specificity of 99%. These results were significantly better than for Phalen’s wrist flexion test (61% and 83%, respectively) and for the sensitivity of Tinel’s test (74%). The positive predictive values of the wrist flexion and median-nerve compression test, which is more important clinically, were 99%, 95% and 81% at population prevalences of 50%, 20% and 5%, respectively. These were significantly better than those of the three other provocative tests at each prevalence.

Electrodiagnostic studies have significant false-positive and false-negative rates in CTS, and therefore provocative tests remain important in its diagnosis. We have shown that wrist flexion combined with the median-nerve compression test at 20 s, is significantly better than the other methods, and may thus be clinically useful.

Changes in interstitial pressure and cross-sectional area of the cubital tunnel and of the ulnar nerve with flexion of the elbow. An experimental study in human cadavera

The purpose of this study was to determine the relationship between the ulnar nerve and the cubital tunnel during flexion of the elbow with use of magnetic resonance imaging and measurements of intraneural and extraneural interstitial pressure. Twenty specimens from human cadavera were studied with the elbow in positions of incremental flexion. With use of magnetic resonance imaging, cross-sectional images were made at each of three anatomical regions of the cubital tunnel: the medial epicondyle, deep to the cubital tunnel aponeurosis, and deep to the flexor carpi ulnaris muscle. The cross-sectional areas of the cubital tunnel and the ulnar nerve were calculated and compared for different positions of elbow flexion. Interstitial pressures were measured with use of ultrasonographic imaging to allow a minimally invasive method of placement of the pressure catheter, both within the cubital tunnel and four centimeters proximal to it, at 10-degree increments from 0 to 130 degrees of elbow flexion. As the elbow was moved from full extension to 135 degrees of flexion, the mean cross-sectional area of the three regions of the cubital tunnel decreased by 30, 39, and 41 per cent and the mean area of the ulnar nerve decreased by 33, 50, and 34 per cent. These changes were significant in all three regions of the cubital tunnel (p < 0.05). The greatest changes occurred in the region beneath the aponeurosis of the cubital tunnel with the elbow at 135 degrees of flexion. The mean intraneural pressure within the cubital tunnel was significantly higher than the mean extraneural pressure when the elbow was flexed 90, 100, 110, and 130 degrees (p < 0.05). With the elbow flexed 130 degrees, the mean intraneural pressure was 45 per cent higher than the mean extraneural pressure (p < 0.001). Similarly, with the elbow flexed 120 degrees or more, the mean intraneural pressure four centimeters proximal to the cubital tunnel was significantly higher than the mean extraneural pressure (p < 0.01). Relative to their lowest values, intraneural pressure increased at smaller angles of flexion than did extraneural pressure, both within the cubital tunnel and proximal to it. With the numbers available, we could not detect any significant difference in intraneural pressure measured, either at the level of the cubital tunnel or four centimeters proximal to it, after release of the aponeurotic roof of the cubital tunnel.

The effects of proximal load on the excursion of autogenous flexor tendon grafts

To determine the relationship between the intrinsic properties of tendon and tendon excursion in 2 types of autogenous tendon grafts, hindpaw intrasynovial and extrasynovial tendons were transferred to the lateral and medial forepaws of adult mongrel dogs (16 experimental and 16 control tendons). After each digit was marked with radiopaque markers, it was placed in a specialized jig, and weights of 25 g, 100 g, or 200 g were applied to the flexor tendons. Specialized radiographs were obtained with the digit in flexion and extension. Tendon excursion and joint rotation were calculated. There were no statistically significant differences between experimental groups for tendon excursion or for joint angular rotation (p > .05). For intrasynovial tendon grafts, the angular rotation per millimeter tendon excursion was 10.9 degrees +/- 2.4 degrees/mm, 9.4 degrees +/- 1.2 degrees/mm, and 9.0 degrees +/- 1.4 degrees/mm with 25-g, 100-g, and 200-g loads, respectively. Comparisons between experimental groups revealed that a statistically significant difference could not be determined (p > .05). With varying proximal loads, both intrasynovial and extrasynovial grafts showed similar amounts of tendon excursion. Variations in proximal load did not significantly influence the amount of excursion within the range of loads tested. Based on these data, it appears that the difference in repair potential for these 2 types of tendon grafts is not related to a differential in the amount of tendon graft excursion following transfer to the synovial space.

The effects of multiple-strand suture methods on the strength and excursion of repaired intrasynovial flexor tendons: a biomechanical study in dogs

This study was designed to determine the effects of in vivo multistrand, multigrasp suture techniques on the strength and gliding of repaired intrasynovial tendons when controlled passive motion rehabilitation was used. Twenty-four adult mongrel dogs were divided into 4 groups and their medial and lateral forepaw flexor tendons were transsected and sutured by either the Savage, the Tajima, the Kessler, or the recently developed 8-strand suture method. The tendon excursion, joint rotation, and tensile properties of the repaired tendons were evaluated biomechanically at 3 and 6 weeks after surgery. It was found that neither time nor suture method significantly effected proximal and distal interphalangeal joint rotation or tendon excursion when the 4 techniques were compared to each other. Normalized load value (experimental/control) was significantly affected by both the suture method and the amount of time after surgery, however. The Savage and 8-strand repair methods had significantly greater strength than did the Tajima method at each time interval (p < .05 for each comparison). In addition, the 8-strand method had significantly greater normalized load values than did the Savage method at each time interval (p < .05 for each comparison). Normalized stiffness (experimental/control) for the 8-strand repair method was significantly greater than that for the Tajima and Savage methods at 3 and 6 weeks after surgery (p < .05). In addition, the normalized stiffness values for the 6-week groups was significantly greater than those for the 3-week groups (p < .05). It was concluded that the method of tendon suture was a significant variable insofar as the regaining of tendon strength was concerned and that the newer low-profile 8-strand repair method significantly expands the safety zone for the application of increased in vivo load during the early stages of rehabilitation.

Flexor digitorum profundus tendon-to-bone repair: an ex vivo biomechanical analysis of 3 pullout suture techniques

Avulsions or distal transsections of the flexor digitorum profundus tendon are typically repaired by direct suture of tendon to the distal phalanx. The tensile properties of tendon-tobone repairs performed in cadaver fingers using 3 common suture patterns, the Bunnell, the Kessler, and the Kleinert techniques, were compared; 3-0 Prolene (monofilament) suture was used. Repairs done using the Kessler pattern had an average yield force of 30 N, compared to 39 N for the Bunnell and Kleinert patterns. Although these average yield forces were greater than that required for active digital flexion, considerable elongation (average, 8 mm) was measured at a force of 20 N. Data indicated that the safety factor achieved with these repair methods is lower than that achieved with modern tendon-to-tendon repair methods. The authors conclude that the common tendon-to-bone repair techniques are insufficient to withstand the higher forces associated with controlled passive and active motion rehabilitation methods that are currently advocated.

The Marshall R. Urist Young Investigator Award. Autogenous flexor tendon grafts. Biologic mechanisms for incorporation

To examine the hypothesis that different types of dense regular connective tissue may have different repair mechanisms within the synovial space, intrasynovial and extrasynovial autogenous donor flexor tendon grafts were placed within the synovial sheaths of the medial and lateral forepaw digits of dogs. Histologic, ultrastructural, biochemical, and biomechanical analyses were done between 10 days and 6 weeks after tendon grafting. Intrasynovial tendon grafts remained viable when transferred to the synovial space and appeared to heal through an intrinsic process with preservation of the gliding surface and improved functional characteristics. Extrasynovial tendon grafts functioned as a scaffolding for the early ingrowth of new vessels and cells. Early cellular necrosis consistently was followed by the ingrowth of fibrovascular adhesions from the periphery. The formation of dense peripheral adhesions, obliterating the gliding surface of the tendon, led to diminished tendon excursion and proximal interphalangeal joint rotation.

The extraosseous and intraosseous arterial anatomy of the adult elbow

We investigated the extraosseous and intraosseous arterial anatomy of the human adult elbow. Twenty-two fresh adult cadaveric upper extremities were studied with a technique of combined India-ink and latex injection followed by chemical débridement. The intraosseous vascularity of twelve extremities was then evaluated with a rapid Spalteholz clearing technique. Our findings demonstrated consistent patterns of extraosseous and intraosseous vascular anatomy, which were organized into three vascular arcades: medial, lateral, and posterior. The medial arcade was formed by the superior and inferior ulnar collateral arteries and the posterior ulnar recurrent artery. The lateral arcade was formed by the radial and middle collateral, radial recurrent, and interosseous recurrent arteries. The posterior arcade was formed by the medial and lateral arcades and the middle collateral artery. The intraosseous circulation of the elbow, which was segmental in organization, appeared to be dependent on the local blood supply. The capitellum and the lateral aspect of the trochlea were supplied by posterior perforating vessels arising from the radial recurrent, radial collateral, and interosseous recurrent arteries. The medial aspect of the trochlea was supplied by a circumferential vascular ring originating from the inferior ulnar collateral artery. Watershed areas were apparent between the blood supplies to the medial and lateral aspects of the distal end of the humerus. The olecranon was richly supplied by vessels coursing along its medial aspect from the posterior ulnar recurrent artery and along its lateral aspect from the interosseous recurrent artery. The radial head had a dual extraosseous blood supply from a single branch of the radial recurrent artery, which supplied the head directly, and from additional vessels from both the radial and the interosseous recurrent artery, which penetrated the capsular insertion at the neck of the radius.

CLINICAL RELEVANCE

Our findings demonstrate that arterial contributions to the intraosseous circulation of the elbow are more specific than previously appreciated. The intraosseous circulation of the elbow is derived mainly from perforating vessels that arise from neighboring extraosseous arteries. These perforating arteries may be damaged by trauma or by extensile dissection during reconstruction of the elbow. An understanding of the extraosseous and intraosseous circulation of the elbow may help to avoid iatrogenic injury to the intraosseous circulation.

Extensive nodular sarcoidosis in the hand

We report an atypical case of nodular sarcoidosis involving both hands. The pattern of extensive involvement of all digits with lesions extending into the pulp spaces has not been reported previously. The diagnosis of sarcoidosis should be considered even in patients presenting with clinically uncharacteristic manifestations.

Displaced intra-articular fractures of the distal aspect of the radius. Long-term results in young adults after open reduction and internal fixation

The purpose of this retrospective study was to determine the long-term functional and radiographic outcomes in a series of young adults (less than forty-five years old) in whom an acute displaced intra-articular fracture of the distal aspect of the radius had been treated with operative reduction and stabilization. Twenty-six fractures in twenty-six patients met the initial inclusion criteria for the study. Twenty-one patients returned for a physical examination, imaging (plain radiographs and computerized tomography scans), and completion of a validated musculoskeletal function assessment questionnaire at a minimum of 5.5 years. The physical examinations were performed by the same observer, who was not involved in the initial care of the patients. The plain radiographs and computerized tomography scans were assessed in a blinded fashion by two independent observers who measured the radiographic parameters with standardized methods. At an average of 7.1 years, osteoarthrosis of the radiocarpal joint was evident on the plain radiographs and computerized tomography scans of sixteen (76 per cent) of the twenty-one wrists. A strong association was found between the development of osteoarthrosis of the radiocarpal joint and residual displacement of articular fragments at the time of osseous union (p < 0.01). However, the functional status at the time of the most recent follow-up, as determined by physical examination and on the basis of the responses on the questionnaire, did not correlate with the magnitude of the residual step and gap displacement at the time of fracture-healing. All patients had a good or excellent functional outcome irrespective of radiographic evidence of osteoarthrosis of the radiocarpal or the distal radio-ulnar joint or non-union of the ulnar styloid process. It appears prudent therefore to base the indications for salvage operative procedures on the presence of severe symptoms or a loss of function rather than on radiographic evidence of osteoarthrosis of the radiocarpal joint.

Radiographic evaluation of osseous displacement following intra-articular fractures of the distal radius: reliability of plain radiography versus computed tomography

This study evaluated the reliability of plain radiography versus computed tomography (CT) for the measurement of small (< 5 mm) intra-articular displacements of distal radius fracture fragments. The plain radiographs and CT scans of 19 acute intra-articular distal radius fractures were used by 5 independent observers, using 2 standardized techniques, to quantify incongruity of the articular surface in a blinded and randomized fashion. Repeat measurements were performed by the same observers 2-4 weeks later, allowing determination of intraclass correlation coefficients (ICC) as a measure of intraobserver and interobserver agreement. The average maximum gap displacement on plain radiographs was 2.1 mm (range, 0.0-15.0 mm, lateral view) and on CT images was 4.9 mm (range, 0.7-17.3 mm, axial view). The average maximum step displacement on plain radiographs was 0.9 mm (range, 0.0-6.4 mm, lateral view) and on CT images was 1.2 mm (range, 0.0-6.0 mm, sagittal view). More reproducible values determining step and gap displacement were obtained when the arc method of measurement was used on CT scans (ICC values, .69-.97) as compared to the longitudinal axis method for plain radiographs (ICC values, .30-.50). For measured displacements of 2 mm or more, our data demonstrated poor correlation between measurements made on CT images and those made on plain radiographs (gap or step displacement > 2 mm, K = 0.21; step displacement > 2 mm, K = 0.21). Thirty percent of measurements from plain radiographs significantly underestimated or overestimated displacement compared to CT scan measurements. From these data, we conclude that CT scanning data, using the arc method of measurement, are more reliable for quantifying articular surface incongruities of the distal radius than are plain radiography measurements.

Quantification of the radial torsion angle with computerized tomography in cadaver specimens

Torsion of a long bone is the twist along its longitudinal axis; torsion of the radius is defined by the angle between the proximal and distal metaphyses in the transverse plane. Measurement of the radial torsion angle provides a means of detection and quantification of malrotation after a fracture. The purpose of the current study was to develop and standardize a technique for the measurement of torsion of the radius. Axial computerized tomographic images of thirty-nine pairs of dry cadaver specimens of normal radii, and an additional four pairs of radii with a unilateral deformity of the distal metaphysis that was consistent with a previous fracture, were studied and a measurement protocol was established. The radial torsion angle was measured by three independent observers on two separate occasions. Reproducibility of the technique was determined with use of the intraclass correlation coefficient to express both interobserver and intraobserver reliability. Consistency of measurements between observers and by the same observer was high, with intraclass correlation coefficients ranging from 0.87 to 0.94. The mean torsion angle for the eighty-two normal radii in the study was 32.6 degrees (95 per cent confidence interval of the mean, 30.3 to 34.9 degrees; range, 1.4 to 58.8 degrees). There were small variations in torsion angle between the two radii of each normal pair (mean side-to-side difference, 4.9 degrees; 95 per cent confidence interval of the mean, 3.5 to 6.3 degrees). The mean torsion angle of the four radii with a malunited fracture was 10.4 degrees (95 per cent confidence interval of the mean, 5.7 to 15.1 degrees), and the mean side-to-side difference in the pairs containing these radii was 24.1 degrees (95 per cent confidence interval of the mean, 8.5 to 39.6 degrees; p < 0.0001 compared with the normal radii).

Tensile properties of canine intrasynovial and extrasynovial flexor tendon autografts

This study compared the biomechanical properties of intrasynovial and extrasynovial flexor tendon autografts in an adult canine model. Flexor digitorum profundus (FDP) tissue from the fifth toe of the hindpaw was harvested and transplanted as an intrasynovial graft to the second toe of the left forepaw of each animal. Peroneus longus tendon from the lateral compartment of the hind leg served as the source for the extrasynovial graft that was transplanted to the fifth toe of each dog's left forepaw. The second and fifth FDP tendons of the right forepaw constituted the respective contralateral controls. Postoperatively, each animal underwent a regimen of daily controlled passive mobilization. Three and 6 weeks after grafting, 6 animals were euthanized and their grafts evaluated for gliding function and tensile properties. Results reveal significantly greater angular rotation of the proximal interphalangeal joint in the digits that received intrasynovial grafts relative to those that received transplanted extrasynovial tendon at both 3 and 6 weeks postoperatively. The linear stiffness of the tendons receiving extrasynovial graft significantly exceeded that of the intrasynovial group. These findings correlated with histologic data that postoperative adhesions existed in the specimens with an extrasynovial graft. In addition, the extrasynovial tendon graft complex exhibited significantly higher ultimate loads than intrasynovial tendon graft complex at 6 weeks.

Biomechanical effects of operative nerve mobilization and transposition in a canine ulnar nerve model

The purpose of this study was to evaluate the effects that operative mobilization and transposition of the ulnar nerve have on both neural excursion and mechanical properties. Twelve dogs underwent ulnar nerve transposition and postoperative casting. Four animals were killed at 3 weeks and four animals were killed at 6 weeks. Four animals had their casts removed at 3 weeks, were allowed to ambulate, and were killed at 6 weeks. Operated and contralateral control nerves were compared. Neural excursion was measured near the elbow and 12 cm proximally. The nerves were harvested and their mechanical properties determined. Repeated measures analysis of variance revealed significant differences in longitudinal excursion between control and experimental groups at both sites. Ultimate strain, ultimate strength, and modulus were significantly reduced in the experimental groups. No differences were seen in cross-sectional area or stiffness between control and experimental groups. Analysis revealed no independent effect of the rehabilitation method. Results of this study indicate that significant changes in neural excursion, ultimate strain, ultimate strength, and modulus occur following ulnar nerve mobilization and transposition and that these changes persist throughout the early postoperative period.

The use of routine wrist radiography in the evaluation of patients with carpal tunnel syndrome

The objective of this study was to evaluate the use of routine wrist radiography in the evaluation of patients with carpal tunnel syndrome (CTS). In the setting of a community-based hand surgery practice, we performed a retrospective review of charts and radiographs for 300 consecutive patients (447 wrists) meeting clinical and electrophysiologic criteria for CTS. Data on all patients included information obtained by the use of medical history questionnaires, physical examinations, nerve conduction studies, and radiographs of the wrist. Abnormalities were noted in 146 of 447 wrist radiographs (33%). Eighty-three (18.6%) had abnormalities that might have been implicated in the development of CTS, although these findings would not alter management. For only 2 of 447 wrists (0.4% of wrists; 0.6% of patients) were there radiographic findings of therapeutic significance. Radiographic charges were calculated to be $5,869 to $20,115 for each finding of therapeutic significance. We conclude that wrist radiographs should not be performed routinely in patients with CTS, owing to the low yield of useful information.