Relative contributions of the supraspinatus cord and strap tendons to shoulder abduction and translation

BACKGROUND

The supraspinatus (SS) is formed by a larger anterior bipennate muscle with a cord-like tendon and a posterior unipennate muscle with a strap-like tendon. There is a tendinous connection between the 2 SS subunits. Yet, the relative mechanical contribution of the SS cord and SS strap musculotendinous units to load transmission and subsequent shoulder abduction force is unknown. We hypothesized that a simulated SS cord vs. an SS strap tear would generate less shoulder abduction force and, further, an intact SS cord would offset the expected abduction loss from an SS strap tear, but the inverse would not be true.

MATERIALS AND METHODS

Twenty fresh-frozen cadaveric specimens were tested in a shoulder simulator with physiological load vectors applied to the upper and lower subscapularis, SS cord, SS strap, infraspinatus, and teres minor. The roles of the SS cord and SS strap muscles were delineated by varying their loads, while keeping constant loads on other muscles. The randomized testing trials included a native condition and 4 test cases that simulated tears by dropping the load and force transfer via the SS cord-to-SS strap connection by adding the load. Testing was completed at both 0° and 30° of abduction. During each test, shoulder abduction force, rotator cuff strains, and humeral translation were measured.

RESULTS

Simulated isolated SS cord and SS strap tears led to a significantly lower shoulder abduction force (P < .001). A simulated cord tear at 0° and 30° reduced the abduction force by 53% and 38%, respectively. A simulated strap tear at 0° and 30° dropped the abduction force by 27% and 23%, respectively. The decline in the abduction force was larger for the SS cord tear vs. SS strap tear (P ≤ .001). An SS cord tear with full-load transfer to the strap was able to recover to native values at both 0° and 30° (P ≥ .288). Likewise, an SS strap tear with full-load transfer to the SS cord showed a similar recovery to native values at both 0° and 30° (P ≥ .155). During full-load transfer, the tendon strain followed the loading pattern. An SS cord tear or SS strap tear did not cause a change in humeral translation (P ≥ .303).

DISCUSSION

The mechanical findings support the efficacy of nonoperative treatment of small (<10 mm) SS tears,11 because an intact SS strap tendon can effectively offset the abduction loss of a torn SS cord tear and vice versa.

The Rotator Cable Does Not Stress Shield the Crescent Area During Shoulder Abduction

BACKGROUND

It is accepted by the orthopaedic community that the rotator cable (RCa) acts as a suspension bridge that stress shields the crescent area (CA). The goal of this study was to determine if the RCa does stress shield the CA during shoulder abduction.

METHODS

The principal strain magnitude and direction in the RCa and CA and shoulder abduction force were measured in 20 cadaveric specimens. Ten specimens underwent a release of the anterior cable insertion followed by a posterior release. In the other 10, a release of the posterior cable insertion was followed by an anterior release. Testing was performed for the native, single-release, and full-release conditions. The thicknesses of the RCa and CA were measured.

RESULTS

Neither the principal strain magnitude nor the strain direction in either the RCa or the CA changed with single or full RCa release (p ≥ 0.493). There were no changes in abduction force after single or full RCa release (p ≥ 0.180). The RCa and CA thicknesses did not differ from one another at any location (p ≥ 0.195).

CONCLUSIONS

The RCa does not act as a suspension bridge and does not stress shield the CA. The CA primarily transfers shoulder abduction force to the greater tuberosity.

CLINICAL RELEVANCE

The CA is important in force transmission during shoulder abduction, and efforts should be made to restore its continuity with a repair or reconstruction.

Return to Play After Distal Biceps Tendon Repair

PURPOSE OF REVIEW

Distal biceps tendon ruptures (DBTR) are uncommon injuries in 40- to 50-year-old men but occur at a younger age in the athlete population. The distal biceps tendon is an important supinator of the forearm and flexor of the elbow. A complete injury results in limiting function in the upper extremity. The current review evaluates the different options in management and the current literature on return to play in athletes.

RECENT FINDINGS

The distal biceps tendon inserts on the posterior aspect of the radial tuberosity as two independent heads. The long head footprint is more proximal and posterior giving it a better lever arm for supination. The short head footprint is more distal and anterior giving it a better lever arm for flexion. Surgical anatomic repair is highly recommended among the athlete population, to restore proper function of the upper extremity. There is scarce literature on return to play among athletes. The most recent studies on high-performance athletes are on National Football League (NFL) players. These studies showed that 84-94% of NFL players returned to play at least one game after distal biceps repair. Compared to matched control groups, there was no difference in the player's performance after surgery. Anatomic repair of DBTR results in excellent outcomes, high return to work, and high rate of return to play among athletes. When compared to matched control groups, NFL players have the performance score and play the same number of games after surgery.

Locating the rotator cable during subacromial arthroscopy: bursal- and articular-sided anatomy

BACKGROUND

The rotator cable (RCa) is an important articular-sided structure of the cuff capsular complex that helps prevent suture pull out during rotator cuff repairs (RCRs) and plays a role in force transmission. Yet, the RCa cannot be located during bursal-sided RCRs. The purpose of this study is to develop a method to locate the RCa in the subacromial space and compare its bursal- and articular-sided dimensions.

METHODS

In 20 fresh-frozen cadaveric specimens, the RCa was found from the articular side, outlined with stitches, and then evaluated from the bursal side using an easily identifiable reference point, the intersection of a line bisecting the supraspinatus (SS) tendon and posterior SS myotendinous junction (MTJ). Four bursal-sided lengths were measured on the SS-bisecting line as well as the RCa's outside anteroposterior base. For the articular-sided measurements, the rotator cuff capsular complex was detached from bone and optically scanned creating 3D solid models. Using the 3D models, 4 articular-sided lengths were made, including the RCa's inside and outside anteroposterior base.

RESULTS

The RCa's medial arch was located 9.9 ± 5.6 mm from the reference point in 10 intact specimens and 4.1 ± 2.4 mm in 10 torn specimens (P = .007). The RCa's width was 10.9 ± 2.1 mm, and the distance from the lateral edge of the RCa to the lateral SS insertion was 13.9 ± 4.8 mm. The bursal- and articular-sided outside anteroposterior base measured 48.1 ± 6.4 mm and 49.6 ± 6.5 mm, respectively (P = .268). The average inside anteroposterior base measurement was 37.3 ± 5.9 mm.

DISCUSSION

The medial arch of the RCa can be reliably located during subacromial arthroscopy using the reference point, analogous to the posterior SS MTJ. The RCa is located 10 mm in intact and 4 mm in torn tendons (P = .007) from the posterior SS MTJ. If the above 6-mm shift in location of the RCa is not taken into consideration during rotator cuff suture placement, it could negatively affect time zero repair strength. The inside anteroposterior base of the RCa measures on average 37 mm; therefore, rotator cuff tears measuring >37 mm are at risk of rupturing part or all of the RCa's 2 humeral attachments, which if not recognized and addressed could impact postoperative function.

Partial Distal Biceps Avulsion Results in a Significant Loss of Supination Force

BACKGROUND

Partial avulsions of the short and/or long head of the distal biceps tendon cause pain and loss of strength. The goal of the present study was to quantify the loss of supination and flexion strength following a series of surgical releases designed to simulate partial and complete short and long head traumatic avulsions.

METHODS

Mechanical testing was performed to measure supination moment arms and flexion force efficiency on 18 adult fresh-frozen specimens in pronation, neutral, and supination. The distal biceps footprint length was divided into 4 equal segments. In 9 specimens (the distal-first group), the tendon was partially cut starting distally by releasing 25%, 50%, and 75% of the insertion site. In the other 9 specimens (the proximal-first group), the releases started proximally. Mechanical testing was performed before and after each release.

RESULTS

Significant decreases in the supination moment arm occurred after a 75% release in the distal-first release group; the decrease was 24% in pronation (p = 0.003) and 10% in neutral (p = 0.043). No significant differences in the supination moment arm (p ≥ 0.079) or in flexion force efficiency (p ≥ 0.058) occurred in the proximal-first group.

CONCLUSIONS

A simulated complete short head avulsion significantly decreased the supination moment arm and therefore supination strength.

CLINICAL RELEVANCE

A mechanical case can be made for repair of partial distal biceps tendon avulsions when the rupture involves ≥75% of the distal insertion site.

The effect of tendon rotation on distal biceps repair

Background

The distal biceps tendon externally rotates from proximal to distal before inserting onto the radius. Our hypothesis is that an externally rotated (anatomic) repair would re-create native supination moment arm and flexion force, whereas an internally rotated (nonanatomic) repair would result in reduced force transmission.

Methods

The mechanical tests performed in this study measured isometric moment arms and elbow flexion force using a validated elbow simulator as previously published. Mechanical testing was performed on 8 native cadaveric elbows (61 ± 15 years). The distal biceps tendons in all specimens were then incised from their footprint and repaired with anatomic and nonanatomic tendon rotations. After each repair, the specimens were retested. The repair sequence was randomly assigned.

Results

Gross observation showed repair site bunching with the nonanatomic repairs. There was no statistical difference in the moment arms between the native, anatomic, and nonanatomic rotations for the 3 forearm angles (P ≥ .352). Analysis showed no statistical difference in flexion force ratio for the elbow at 90° (P ≥ .283).

Discussion

The study showed that biceps tendon rotation does not play a role in supination moment arm or flexion force. Twisting the distal biceps tendon around the tendon axis does not change the direction of its applied force on the tuberosity. Tendon bunching in nonanatomic reattachments increases repair site width, which may lead to tendon-ulnar impingement during forearm rotation.

Do we really need to order magnetic resonance imaging? Shoulder surgeon ultrasound practice patterns and beliefs

Background

Despite significant benefits, many orthopedic surgeons are hesitant to incorporate diagnostic ultrasound into their practice. This may be because of a lack of comfort, knowledge, and/or training. The purpose of this study was to analyze practice patterns regarding the use of shoulder ultrasound by orthopedic surgeons to diagnose rotator cuff tears.

Materials and methods

We conducted a survey of the members of the American Shoulder and Elbow Surgeons (ASES) regarding their use of ultrasound. A systematic review of the literature on the use of ultrasound in the shoulder by orthopedic surgeons was also performed.

Results

Of the members of ASES responding to the survey, 55% are using ultrasound for diagnostic purposes in the shoulder. The leading reason for not using ultrasound as the sole imaging modality prior to performing rotator cuff repair was lack of confidence in the ability to determine the reparability of the tear (83%). Our systematic review showed that for an orthopedic surgeon diagnosing a full-thickness rotator cuff tear, the mean sensitivity was 92% and mean specificity was 89%.

Conclusions

Many ASES surgeons are not using ultrasound in the shoulder despite its many potential benefits over magnetic resonance imaging. This is because of a lack of confidence in the ability to quantify fatty infiltration, muscle atrophy, and the level of retraction medial to the acromion. Our systematic review showed that orthopedic surgeons can be accurate in the diagnosis of full-thickness rotator cuff tears. Future research should focus on defining parameters of shoulder ultrasound associated with rotator cuff tendon reparability. Educating surgeons on ultrasound technique, cost, and evidence may be a promising strategy to enhance the value in musculoskeletal care delivery.

Clinical and functional impairment after nonoperative treatment of distal biceps ruptures

BACKGROUND

Clinical and functional impairment after nonoperative treatment of distal biceps ruptures is not well understood. The goal of this study was to measure patients' perceived disability, kinematic adjustment, and forearm supination power after nonoperative treatment of distal biceps ruptures.

METHODS

Fourteen individuals after nonoperative treatment of distal biceps ruptures were matched to a control group of 18 uninjured volunteers. Both groups prospectively completed the Disabilities of the Arm, Shoulder and Hand (DASH), Single Assessment Numerical Evaluation (SANE), and Biceps Disability Questionnaire. Both performed a new timed isotonic supination test that was designed to simulate activities of daily life. The isotonic torque dynamometer measures the supination arc, center of supination arc, torque, angular velocity, and power. Motion analysis quantifies forearm and shoulder contributions to the arc of supination.

RESULTS

The nonoperative treated group's DASH (23.2 ± 10.3) and SANE (59.6 ± 16.2) scores demonstrated a clinical meaningful impairment. The control group showed no significant differences in kinematic values between dominant and nondominant arms (P = .854). The nonoperative biceps ruptured arms, compared with their uninjured arms, changed supination motion by decreasing the supination arc (P ≤ .036), shifting the center of supination arc to a more pronated position (P ≤ .030), and increasing the shoulder contribution to rotation (P ≤ .001); despite this adaptation, their average corrected power of supination decreased by 47% (P = .001).

CONCLUSION

Patients should understand that nonoperative treatment for distal biceps ruptures will result in varying degrees of functional loss as measured by the DASH, SANE, and Biceps Disability Questionnaire, change their supination kinematics during repetitive tasks, and that they will lose 47% of their supination power.

Distal Biceps Tendon Anatomic Repair

Distal biceps injuries, which usually occur in active middle-aged men, can result in chronic pain and loss of supination and flexion strength³,⁴. Surgical repair of a ruptured distal biceps tendon can reliably decrease pain and improve strength compared with nonoperative management³,⁴. However, even following successful healing and rehabilitation of a surgically repaired biceps tendon, full supination strength is rarely restored⁵-⁷. The expected outcome following distal biceps repair using a traditional anterior approach is a measurable loss of rotational strength, especially from neutral to supinated positions⁵,⁷. This deficit can lead to difficulty with occupational and recreational activities⁵,⁸. The center of an uninjured biceps tendon inserts into the radial tuberosity 6.7 mm anterior to its apex⁹,¹⁰. This posterior location forces the biceps tendon to wrap around the radial protuberance during pronation, thus utilizing the protuberance as a mechanical cam during forceful forearm supination¹⁰,¹¹. The distal biceps tendon comprises a medial short head and lateral long head; the 2 heads are continuations of the proximal muscles²,²⁰,²¹. The short head inserts distal to the long head on their radial attachment site²,²⁰,²¹. Performing a distal biceps repair via an anterior approach typically places the center of the reattachment site 12.9 mm anterior to its apex or approximately 6 mm anterior to an uninjured control tendon⁹. This shifts the repair site from its anatomic location (posterior to the radial protuberance) to a new nonanatomic location (on top of the protuberance). This anterior reattachment location decreases the cam effect of the radial protuberance, resulting in an average supination loss of 10% in neutral rotation and 33% in 60° of supination⁷,¹⁰. A posterior approach to the radial tuberosity using 2 separate intramedullary buttons for the short and long heads reliably positions the distal biceps insertion at its anatomic footprint, which is posterior to the radial protuberance⁹,¹⁰,¹¹. This technique has been named the distal biceps tendon anatomic repair. Not only does it restore the normal supination cam effect of the radial protuberance, but it also provides superior initial fixation strength, with load to failure strength similar to the native tendon¹. The distal biceps anatomic repair can be divided into the following 9 key steps: Step 1: Preoperative planning; Step 2: Positioning; Step 3: Identifying and retrieving the tendon; Step 4: Preparing the 2 heads of the tendon; Step 5: Posterior exposure of tendon footprint; Step 6: Drilling the short and long-head drill holes; Step 7: Passage of the tendon; Step 8: Unicortical button fixation; Step 9: Alternative fixation: cortical trough; and Step 10: Postoperative management.

Distal biceps tendon history, updates, and controversies: from the closed American Shoulder and Elbow Surgeons meeting-2015

Understanding of the distal biceps anatomy, mechanics, and biology during the last 75 years has greatly improved the physician's ability to advise and to treat patients with ruptured distal tendons. The goal of this paper is to review the past and current advances on complete distal biceps ruptures as well as controversies and future directions that were discussed and debated during the closed American Shoulder and Elbow Surgeons meeting in 2015.

Factors That Determine Supination Strength Following Distal Biceps Repair

BACKGROUND

Supination weakness commonly occurs after a distal biceps repair. The goal of this study was to identify factors that could influence postoperative supination strength through a full arc of forearm rotation.

METHODS

Fifteen patients were prospectively studied and underwent a biceps repair using a posterior approach; this cohort was compared with a randomized selection of 17 anterior repair subjects. All patients underwent postoperative magnetic resonance imaging (MRI). Quantitative MRI analysis determined the insertion site angle of the tendon and supinator fat content. Supination strength was measured in 3 forearm positions. A multiple linear regression analysis was performed to determine the effect of all factors on supination strength.

RESULTS

The anterior group had a significantly higher nonanatomic insertion site angle of the tendon than the control group and the posterior group (p < 0.001). The posterior group had significantly greater supinator fat content (p ≤ 0.019) than both the control group and the anterior group. After repair, the posterior group had significantly greater supination strength than the anterior group (p = 0.027). Multiple regression analysis (r = 0.765) found that an anatomic reinsertion of the ruptured tendon (β = 1.159; p < 0.001), posterior approach (β = 0.484; p = 0.043), and limited supinator muscle fat content (β = 0.360; p = 0.013) were significant predictors of the restoration of supination strength in 60° of supination.

CONCLUSIONS

Future directions for distal biceps tendon repair techniques should focus on restoring an anatomic reattachment site while limiting supinator damage.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Importance of Preserving the Radial Tuberosity During Distal Biceps Repair

BACKGROUND

The radial tuberosity contributes to the biceps supination moment arm and the elbow flexion moment. The purpose of our study was to compare the impact of a cortical bone trough versus an anatomic repair on measurements of the forearm supination moment arm and elbow flexion force efficiency. Our hypothesis was that a trough repair would decrease the tuberosity height, the native biceps supination moment arm, and elbow flexion force efficiency compared with an anatomic repair.

METHODS

The isometric supination moment arm and elbow flexion force efficiency were measured in ten matched pairs of cadaveric upper limbs. After testing, the geometry of the proximal aspect of the radius was reconstructed with use of stereophotogrammetry. All of the repair sites were three-dimensionally reconstructed to quantify the disturbance of the trough on native anatomy. The tuberosity distance was defined as the distance between the central axis of the radius and the centroid of the respective repair site.

RESULTS

Specimens with a trough repair had a 27% lower supination moment arm at 60° of supination (p = 0.036). There were no differences found for pronation or neutral forearm positioning (p > 0.235). Flexion force efficiency was not significantly different between the trough and anatomic repair groups. The average tuberosity distance was 11.0 ± 2.1 mm for the anatomic repairs and 8.3 ± 1.4 mm for the trough repairs (p = 0.003). The percentage of distance lost due to the trough was 25%. Furthermore, the supination moment arm in the supinated position was significantly correlated with the tuberosity distance.

CONCLUSIONS

The trough technique resulted in a significant decrease (p = 0.036) in the moment arm of a 60° supinated forearm and a significant reduction (p = 0.003) in radial tuberosity height. The loss of the supination moment arm was correlated with the decrease in tuberosity height, providing evidence that the radial protuberance acts as a mechanical cam.

CLINICAL RELEVANCE

The anterior protuberance of the radial tuberosity functions as a supination cam; therefore, consideration should be given to preserve its topographical anatomy during a distal biceps repair.

Management of full-thickness rotator cuff tears: appropriate use criteria

BACKGROUND

The appropriate use criteria (AUC) were developed for full-thickness rotator cuff tears to determine when it is reasonable to recommend nonoperative care, partial repair/débridement, repair, reconstruction, or arthroplasty. The goal of this report was to interpret and summarize the results of the AUC process into clinically relevant terms.

METHODS

Using the results of the AUC methodology, we systematically interpreted the clinical importance attributed to the various patient and pathologic variables. We then assessed the combination of considerations that would justify the various treatment options using "preference tables."

RESULTS

A nonoperative program was appropriate if the patient had a positive response to conservative care. However, a repair could be maybe appropriate was also accepted. Rotator cuff repair was appropriate when conservative treatment failed in symptomatic patients. Reconstructive measures were recognized primarily in those with chronic massive tears. Most found arthroplasty maybe appropriate only in healthy patients, pseudoparalysis, and chronic massive tears. Surprisingly, neither factors that decreased healing nor adversely affected outcome had a strong influence on the panel's treatment recommendations.

CONCLUSIONS

The AUC process accounts for clinical experience and considers individual patient and pathologic characteristics of the condition. Overall, the outcome of this exercise does support the current practice for the management of rotator cuff tears (ie, repair of symptomatic tears). However, the minimal importance given to patient and pathologic considerations, well documented to influence outcome, prompts an ongoing effort to refine this important and clinically relevant process.

Management of rotator cuff tears

Every year approximately 18 million Americans report shoulder pain, a large percentage of which are a result of rotator cuff disease. Rotator cuff tear progression can be difficult to predict. Factors associated with tear enlargement include increasing symptoms, advanced age, involvement of 2 or more tendons, and rotator cable lesion. Nonsurgical treatment can be effective for patients with full-thickness tears. When conservative treatment fails, surgical repair provides a reliable treatment alternative. Recurrent tears after surgery can compromise outcomes, particularly for younger patients with physically demanding occupations. Revision surgery provides satisfactory results for those with symptomatic re-tears. If the tear is deemed irreparable, addressing concomitant biceps pathology or performing partial repairs can reliably improve pain and potentially reverse pseudoparalysis. The reverse shoulder arthroplasty has limited indications in the setting of rotator cuff tears and should be reserved for patients with painful pseudoparalysis and associated arthropathy.

Effect of lesser tuberosity osteotomy size and repair construct during total shoulder arthroplasty

BACKGROUND

Lesser tuberosity osteotomy has been shown to decrease postoperative subscapularis dysfunction. The purpose of this study was to determine the effect of osteotomy thickness and suture configuration on repair integrity.

MATERIALS AND METHODS

One side of 12 matched-pair cadaveric shoulders was randomly assigned to either a thick osteotomy (100% of lesser tuberosity height) or a thin osteotomy (50% of height). Both sides of the matched pairs were given the same repair, either (1) compression sutures or (2) compression sutures plus 1 tension suture. This created 4 groups of 6 paired specimens. Computed tomography imaging was used to measure tuberosity dimensions before and after osteotomy to validate fragment height and area. The repairs were loaded cyclically and then loaded to failure. A video system measured fragment displacement. The percent area of osteotomy contact was calculated from the computed tomography and displacement data.

RESULTS

The average initial displacement was less in the thin osteotomy groups (P = .011). Adding a tension suture negated this difference. A significant number of thin repair sites compared with thick repair sites remained intact during load-to-failure testing (P = .001). No difference occurred because of maximum load between the repair groups (P = .401), and construct stiffness was greater when a tension suture was used (P = .032). The percent area of osteotomy contact showed no differences between the osteotomy (P = .431) and repair (P = .251) groups.

CONCLUSION

The study showed that thin osteotomies displaced less than thick osteotomies. Adding a tension band improved construct stability and eliminated some failure modes. Our ideal repair was a thin wafer with both tension and compression sutures. This construct had smaller total displacement, a high osteotomy percent contact area, and a high maximum load.

Reverse shoulder arthroplasty

The reverse shoulder arthroplasty is considered to be one of the most significant technological advancements in shoulder reconstructive surgery over the past 30 years. It is able to successfully decrease pain and improve function for patients with rotator cuff-deficient shoulders. The glenoid is transformed into a sphere that articulates with a humeral socket. The current reverse prosthesis shifts the center of rotation more medial and distal, improving the deltoid's mechanical advantage. This design has resulted in successful improvement in both active shoulder elevation and in quality of life.

The distal biceps tendon

Distal biceps tendon ruptures continue to be an important injury seen and treated by upper extremity surgeons. Since the mid-1980s, the emphasis has been placed on techniques that limit complications or improve initial tendon-to-bone fixation strength. Recently, basic science research has expanded the knowledge base regarding the biceps tendon structure, footprint anatomy, and biomechanics. Clinical data have further delineated the results of conservative and surgical management of both partial and complete tears in acute or chronic states. The current literature on the distal biceps tendon is described in detail.

Repaired distal biceps magnetic resonance imaging anatomy compared with outcome

BACKGROUND

This study examined the magnetic resonance imaging (MRI) appearance of an anterior incision distal biceps tendon repair and evaluated the association between appearance and outcome.

MATERIALS AND METHODS

Nineteen patients were randomly recruited to undergo an elbow MRI from a single-surgeon series of distal biceps repairs using an anterior approach. Tendon healing was evaluated by the integrity of the repair, the amount of heterogeneity within the tendon substance, and the presence of heterotopic bone. The angle of tendon insertion on the tuberosity was used to quantify the tendon location from the MRI in the patients and in 10 healthy volunteers. All patients completed the Disabilities of Arm, Shoulder and Hand (DASH) and a visual analog pain scale (VAPS), and 17 patients underwent isometric supination strength testing. MRI findings were statistically compared with the outcome scores.

RESULTS

All of the repairs healed to cortical bone. High intrasubstance heterogeneity or heterotopic bone was present in 11 patients (58%). The insertion site angle of the repaired tendons was 73° more anterior than the uninjured controls (P < .001). Average DASH was 7.7 (range, 0-49.2) and VAPS was 0.7 (range, 0-5). At 60° of forearm supination, supination strength was 67% of the uninjured side (P < .01). No significant differences in DASH or VAPS scores were found between groups based on tendon appearance.

CONCLUSIONS

The distal biceps tendon predictably heals to cortical bone but demonstrates a wide variability in overall morphology that does not influence DASH or VAPS scores. A significant decrease in strength at 60° of supination appears to be an effect of an anterior tendon reattachment location.

Anatomic and biomechanical analysis of the short and long head components of the distal biceps tendon

HYPOTHESIS

The short head bundle of the distal biceps tendon is more efficient at elbow flexion, and the long head is more efficient at forearm supination.

METHODS

The short and long head bundles of the distal biceps tendon were separated to the bicipital tuberosity in 6 cadavers. The area and centroid of each bundle insertion were computed from surface points measured within each footprint. Each bundle was individually loaded. The supination torque and flexion load generated were recorded at 90° of elbow flexion. The slope of the torque generated versus biceps load was used to define the supination moment arm. The ratio of the flexion load generated to biceps load applied was used to define the relative flexion efficiency.

RESULTS

The short head insertion was positioned distal and anterior relative to the long head and typically included the apex of the tuberosity. The areas of the long and short heads were 59 ± 15 and 94 ± 44 mm(2) (P = .07), respectively. The long head moment arm was significantly higher in supination. The short head had a significantly higher moment arm in neutral and pronation. The ratio of the flexion load to biceps load was 15% higher for the short head.

CONCLUSION

The short and long heads of the biceps have distinct insertions. The short head's insertion allows it to be relatively more efficient at elbow flexion at 90°. In the neutral and pronated forearm, the short head is the relatively more efficient supinator. In the supinated forearm, the long head becomes relatively more efficient at supination.

Arthroscopic treatment of rotator cuff disease

The goal of this article is to summarize the current concepts on rotator cuff disease with an emphasis on arthroscopic treatment. Most rotator cuff tears are the result of an ongoing attritional process. Once present, a tear is likely to gradually increase in size. Partial-thickness and subscapularis tears can both be successfully treated arthroscopically if conservative management fails. Partial tears involving greater than 50% of tendon thickness should be repaired. Articular-sided partial tears involving less than 50% of the rotator cuff can reliably be treated with debridement. A more aggressive approach should be considered for low-grade tears (<50%) if they occur on the bursal side. Biomechanical and anatomic studies have shown clear superiority with dual-row fixation compared with single-row techniques. However, current studies have yet to show clear clinical advantage with dual-row over single-row repairs. Biceps tenotomy or tenodesis can reliably provide symptomatic improvement in patients with irreparable massive tears. True pseudoparalysis of the shoulder is a contraindication to this procedure alone and other alternatives should be considered.

The effect of biceps reattachment site

BACKGROUND

We hypothesize that an anatomic repair of the distal biceps tendon would recreate native tendon moment arm and forearm rotation, while a nonanatomic insertion would compromise moment arm and forearm rotation.

METHODS

Isometric supination torque was measured at 60° of pronation, neutral, and 60° of supination for the native distal biceps tendon and 4 repair points in 6 cadaveric specimens using a computer controlled elbow simulator. The slope of the regression line fitted to the torque versus biceps load data was used to define the moment arm for each attachment location. Range of motion testing was performed by incrementally loading the biceps, while measuring the supination motion generated using a digital goniometer.

RESULTS

Tendon location and forearm position significantly affected the moment arm of the biceps (P < .05). Anatomic repair in all forearm positions showed no significant difference from the native insertion. Moment arm for an anterior center repair was significantly lower in supination (-97%) and neutral (-27%) and also produced significantly less supination motion. No difference was observed between all tendon locations in pronation.

CONCLUSIONS

Reattachment of the biceps to its anatomic location, as opposed to a more anterior central position, is critical in reestablishing native tendon biomechanics. Clinically, these findings would suggest that patients with a biceps repair might experience the most weakness in a supinated position without experiencing a deficit in the pronated forearm.

Proper insertion angle is essential to prevent intra-articular protrusion of a knotless suture anchor in shoulder rotator cuff repair

The advent of new arthroscopic devices has led to the development of novel techniques of arthroscopic rotator cuff repair. However, failure to recognize specific technical aspects and improper application of these devices can lead to complications. We report a case of intra-articular protrusion of knotless anchors (PEEK PushLock SP, 4.5 x 18.5 mm; Arthrex, Naples, FL), used in the lateral row of a suture-bridging technique for arthroscopic rotator cuff repair. This case draws attention to the increased length of such devices when compared with traditional suture anchors, the technical aspects of proper device use, the possible patient-related factors such as implant-patient size mismatch, and the importance of additional imaging for the investigation of failure to progress postoperatively.

Elbow arthritis: current concepts

The purpose of this article is to provide an update and analyze current management, treatment options, and outcomes of elbow arthritis. This article focuses on studies that have been published in the past 5 years. Nonoperative management may provide symptomatic relief in the early stages of the disease process for most patients. Surgical treatment is guided by disease etiology and severity, patient age, and functional demands. Arthroscopic or open synovectomy, debridement arthroplasty, and interposition arthroplasty are generally recommended for the young and active patient population, whereas for low-demand and elderly patients with end-stage painful arthritis, total elbow arthroplasty is considered a more suitable surgical option. Advances in arthroscopic techniques and implant design have led to substantial improvements in treatment of elbow arthritis.

Plain radiographs are inadequate to identify overlengthening with a radial head prosthesis

PURPOSE

A correctly sized radial head implant helps restore more normal elbow motion and load distribution and allows the collateral ligaments to heal in an anatomic position. No single method of measurement has been agreed on. We hypothesized that plain radiographs could be used to evaluate the appropriate length of a radial head prosthesis when we simulated different patterns of ligament disruption.

METHODS

Osteotomies of the medial and lateral condyles were created in 6 cadaver specimens to simulate 4 conditions: ulnar collateral ligament (UCL) and lateral ulnar collateral ligament (LUCL) intact, UCL intact, LUCL intact, and UCL and LUCL disrupted. Radial heads were resected and replaced with correctly or incorrectly sized monopolar radial head implants. Radiographs were taken after simulated ligament injury with a radial head prosthesis that was either 2 mm too short, the appropriate length, or too long by either 2 or 4 mm. Measurements were recorded between radiographic markers to determine ulnohumeral joint displacement. A 4 x 4 x 2 repeated-measures analysis of variance was performed, as well as post hoc analyses using Tukey's honest significant difference test, to determine statistically significant changes in our radiographic measurements.

RESULTS

Results showed that disruption of at least 1 ligament alters the ulnohumeral joint separation on the lateral but not on the anteroposterior radiograph. Overlengthening the radial head did not result in a statistically significant change in ulnohumeral space.

CONCLUSIONS

Replicating radial length is an important but sometimes difficult step during radial head replacement. Standard radiographic assessment of the ulnohumeral joint will not demonstrate marked changes in the ulnohumeral space when the implant is underlengthened by 2 mm or overlengthened by as much as 4 mm, as long as the joint remains located. Disruption of at least 1 collateral ligament alters the ulnohumeral joint separation on the lateral but not on the anteroposterior radiograph.

Flexor tendon injuries following locked volar plating of distal radius fractures

We present 2 cases showing that flexor pollicis longus and flexor digitorum profundus index injury can occur after placement of 2 commonly used locked volar plates. In contrast with the literature, the radii healed in an anatomic position without plate lift-off. The patients presented 6 and 8 months after surgery with new onset of radial wrist pain and tenderness at the site of the plate and absence or weakness of the flexor pollicis longus. In both cases, the plate was positioned anterior to the distal radial rim on the lateral radiograph. We suggest close follow-up of all fractures in which the distal end of the plate is anterior to the radial rim and removal of hardware if symptoms suggest tendon irritation.

Arthrodesis of the thumb metacarpophalangeal joint using a cannulated screw and threaded washer

We describe a technique of arthrodesis of the thumb metacarpophalangeal joint that we performed in 26 patients. Indications for surgery were instability (6 patients), chronic instability with secondary degenerative joint disease (6), osteoarthritis (6), inflammatory arthritis (7), and paralytic boutonniere (1). The technique uses the cup-and-cone method of decortication and positioning with the internal fixation using a 3.0-mm partially threaded cannulated screw and threaded washer (Synthes, Paoli, PA). Twenty-five of 26 joints had clinical and radiographic fusion. Average time to radiographic fusion for 24 patients (1 nonunion, 1 patient without x-rays until 4 months) was 10 weeks. Long-term follow-up evaluation was available for 20 patients and averaged 32 months (range, 21-44 months). All 20 had stable radiographic fusion with maintenance of the fusion angle. There were no infections and no need for hardware removal. Our results indicate that this technique for arthrodesis of the thumb metacarpophalangeal joint is effective and reliable, is accomplished easily, and has a low incidence of complications.

Effect of growth factors on the proliferation of ligament fibroblasts from skeletally mature rabbits

Growth factors have been shown to stimulate fibroblast proliferation during wound and ligament healing. In this study, we analyzed individual effects of eight growth factors in vitro on the proliferation of fibroblasts from the medial collateral (MCL) and anterior cruciate (ACL) ligaments of skeletally mature rabbits. We compared the proliferative response of growth factor-treated and nontreated fibroblasts of both ligaments. The growth-factor treated fibroblasts of the MCL and ACL were also compared. We found that the fibroblasts exposed to epidermal growth factor, basic fibroblast growth factor and platelet-derived growth factor-BB proliferated significantly more than untreated fibroblasts. Acidic fibroblast growth factor at a dose of 1.0 ng/ml caused significant increases in fibroblast proliferation only in the MCL. Transforming growth factor-beta 1, insulin-like growth factor-1, platelet-derived growth factor-AA, and interleukin-1 alpha did not significantly stimulate fibroblast proliferation. MCL fibroblasts generally did not proliferate significantly more than ACL fibroblasts with the exception of MCL fibroblasts exposed to the highest doses of basic fibroblast growth factor, acidic fibroblast growth factor and platelet-derived growth factor-BB. The data were also compared with those obtained earlier using fibroblasts from skeletally immature rabbits (Schmidt et al., JOR 1995). The proliferative response of both the MCL and the ACL fibroblasts was found to decrease with skeletal maturation. Thus, our findings suggest that animal age and fibroblast origin are important factors in determining the proliferative response to growth factors.

Hemodynamics, intramucosal pH and regulators of circulation during perioperative epidural analgesia

PURPOSE

To evaluate the effects of perioperative epidural analgesia on hemodynamics, splanchnic perfusion and regulators of circulation.

METHODS

Twenty patients undergoing aortic surgery were randomised into two groups: epidural analgesia group (EAG): epidural analgesia with bupivacaine (15 ml, 0.125%) was started before surgery. Eight and 16 hr postoperatively 10 ml bupivacaine 0.125% and 1 mg morphine were given. Control group (COG): patients received no epidural catheter. Monitoring included pulmonary artery catheter and gastric tonometer. Norepinephrine, epinephrine, renin, ADH, ANP and endothelin were measured: before epidural analgesia (T0), before aortic clamping (T1), 20 min after aortic clamping (T2), after declamping the first leg (T3), at end of surgery (T4), one hour (T5) and 24 hr postoperatively (T6).

RESULTS

At T5 mean arterial blood pressure decreased in EAG compared with baseline (86 +/- 16 to 75 +/- 8 mmHg) and compared with COG (75 +/- 8 vs 84 +/- 11 mmHg). At T2 pulmonary capillary wedge pressure and cardiac index increased and at T6 decreased in both groups. Systemic vascular resistance decreased at T I and at T3-T5 in EAG compared with COG and at T1 and T3-T6 to baseline (1472 +/- 448 to 1027 +/- 184 dyn x sec x cm(-5) x m(-2)). In EAG and in COG, pHi decreased compared with baseline but without group differences. In both groups, epinephrine, norepinephrine, renin, and ADH levels increased from baseline. Endothelin and ANP levels showed no changes.

CONCLUSIONS

Perioperatively administrated epidural bupivacaine has no beneficially effects on hemodynamics, pHi or release of regulators of circulation.

Low-flow desflurane and sevoflurane anesthesia minimally affect hepatic integrity and function in elderly patients

Hepatic blood flow is reduced in a dose-related manner by all inhaled anesthetics now in use. We assessed hepatic function in elderly patients anesthetized with desflurane or sevoflurane. We measured the cytosolic liver enzyme alpha glutathione S-transferase (alpha GST), the formation of the lidocaine metabolite monoethylglycinexylidide (MEGX), and gastric mucosal tonometry-derived variables as sensitive markers of hepatic function and splanchnic perfusion. Thirty patients, 70 to 90 yr old, were allocated randomly to receive desflurane or sevoflurane anesthesia. Anesthetic exposure ranged from 2.1-4.5 minimum alveolar concentration hours. No significant changes in standard liver enzyme markers were seen throughout the study. In both anesthetic groups, tonometric measurements showed a significant decrease from baseline in regional PCO(2), regional to arterial difference in PCO(2), and intramucosal pH at 90 min after skin incision. alpha GST concentrations increased significantly in both groups (desflurane: median peak concentrations 5.8 microg/L [25th, 75th percentile 5.3 microg/L, 7.2 microg/L]; sevoflurane: 7.0 microg/L [5.8 microg/L, 7.3 microg/L]) without showing differences between both anesthetic groups. A return to baseline values in tonometric values and alpha GST levels was seen 24 h postoperatively. MEGX formation did not change significantly after surgery. Median MEGX concentrations postoperatively were 70.0 ng/mL (56.2 ng/mL, 102.0 ng/mL) and 70.0 ng/mL (60.0 ng/mL, 94.2 ng/mL) in the desflurane and sevoflurane groups, respectively. We conclude that, overall, liver function in elderly patients is well preserved during desflurane and sevoflurane anesthesia. Increased serum levels of alpha GST and changes of gastric tonometry-derived variables imply a reduction in splanchnic perfusion, leading to a temporary impairment of hepatocyte oxygenation.

IMPLICATIONS

We measured the lidocaine metabolite monoethylglycinexylidide, the cytosolic liver enzyme, alpha glutathione S-transferase, and gastric mucosal tonometry-derived variables to evaluate the effects of desflurane and sevoflurane on hepatic function in elderly patients. Liver function was well preserved, whereas increased alpha glutathione S-transferase levels and changes in tonometry-derived variables indicated a reduction in splanchnic blood flow and a temporary impairment of hepatocyte oxygenation for both anesthetics.

Influence of dopexamine on hemodynamics, intramucosal pH, and regulators of the macrocirculation and microcirculation in patients undergoing abdominal aortic surgery

OBJECTIVE

To investigate whether dopexamine hydrochloride beneficially influences splanchnic perfusion and regulators of the macrocirculation and microcirculation in patients undergoing surgery of the abdominal aorta.

DESIGN

Prospective, blinded, and randomized study.

SETTING

University-affiliated hospital.

PARTICIPANTS

Twenty patients undergoing elective abdominal aortic surgery.

INTERVENTIONS

The patients were randomized to one of two groups. In the dopexamine group (DOP, n = 10), dopexamine, 1 microg/kg/min, was started before surgery and continued for 24 hours. In the control group (COG, n = 10), patients received saline solution as placebo. Extensive hemodynamic monitoring was carried out using a pulmonary artery catheter, and intramucosal pH was measured using a gastric tonometer. From arterial blood samples, important regulators of the circulation were measured before dopexamine was administered (T0), before aortic clamping (T1), 20 minutes after aortic clamping (T2), after declamping the first leg (T3), at the end of surgery (T4), 1 hour postoperatively (T5), and 24 hours postoperatively (T6).

MEASUREMENTS AND MAIN RESULTS

Heart rate increased significantly in DOP (63+/-16 to 84+/-18 beats/min). At T5, mean pulmonary artery pressure was significantly lower in DOP (15+/-6 mmHg) than in COG (22+/-6 mmHg). During aortic clamping, pulmonary capillary wedge pressure increased significantly in both groups. Cardiac index increased significantly from baseline only in the dopexamine patients. No significant differences between the groups were seen with regard to oxygenation parameters and intramucosal pH. Renin plasma levels increased significantly only in COG (46+/-32 to 99+/-55 microU/mL). Endothelin and atrial natriuretic peptide plasma levels showed no significant differences between the two groups. Atrial natriuretic peptide increased significantly only in DOP (366+/-171 pg/mL; COG, 159+/-71 pg/mL). Antidiuretic hormone, norepinephrine, and epinephrine plasma levels increased significantly from baseline in both groups, without showing significant differences between the groups.

CONCLUSIONS

In patients undergoing abdominal aortic surgery, prophylactic perioperative administration of dopexamine hydrochloride produced effects on hemodynamics but without improving oxygenation and intramucosal pH. From the measured regulators of the circulation, only renin was beneficially affected.

Basal joint arthroplasty using an allograft tendon interposition versus no interposition: a radiographic, vascular, and histologic study

To assess the role of a tendon spacer that fills the trapezial void, the trapeziums were excised and anterior oblique ligaments were reconstructed in 25 monkeys. In addition to the ligament reconstruction, 20 of the monkeys had the trapezial void filled with a tendon allograft. The trapezial space was investigated at 0, 3, 6, 15, and 40 weeks using routine histologic staining, arterial perfusion (Spalteholz), and standardized radiographs. There was a statistically greater decline in trapezial height in the animals without tendon interposition allografts. The tendon grafts became progressively neovascularized and populated with fibroblasts. By 40 weeks, the allograft was no longer a folded tendon but a homogeneous mass of collagen, fibroblasts, and capillaries. The specimens without an interpositional tendon graft had loose fibroadipose tissue filling the carpal void. Polarized light microscopy showed fibers crossing the subchondral bone and moving into the adjacent fibrous spacer in the specimens implanted with a tendon graft. The results indicate that filling the trapezial void with an interposition tendon spacer may aid in maintaining normal wrist anatomy.

A comparison of urapidil, clonidine, meperidine and placebo in preventing postanesthetic shivering

This placebo-controlled study was performed to evaluate the efficacy of urapidil compared with clonidine and meperidine in preventing postanesthetic shivering, which is common after anesthesia administration and may be very distressing. We studied 120 patients undergoing elective abdominal or orthopedic surgery under standardized general anesthesia. After surgery, patients were randomly assigned to one of four groups (each group n = 30) using a double-blinded protocol: Group A received 0.2 mg/kg urapidil; Group B, 3 microg/kg clonidine; Group C, 0.4 mg/kg meperidine; and Group D, saline 0.9% as placebo. Postanesthetic shivering was scored by using a five-point scale. Clonidine and meperidine significantly reduced the incidence and the severity of shivering in comparison with placebo, whereas there were no significant differences between the urapidil and placebo groups. Both clonidine and meperidine caused a significantly prolonged emergence time (13.4 +/- 5.8 and 13. 3 +/- 5.0 min, respectively) compared with placebo (10.4 +/- 5.3 min) and urapidil (11.4 +/- 2.9 min). We confirmed that both clonidine and meperidine are effective in preventing postanesthetic shivering, whereas urapidil, in our setting and dosage, was not effective. Patients who received clonidine or meperidine had a prolonged emergence time. In the dosage used, urapidil seems to be unable to prevent postanesthetic shivering.

IMPLICATIONS

Shivering (irregular muscle activity) is common after surgery and anesthesia. This study compared urapidil (an antihypertensive drug) as a prophylaxis with two established antishivering drugs (meperidine and clonidine) and placebo. In the dosage used, we were unable to show a significant benefit of urapidil.

Acute phase response to nitroprusside-induced controlled hypotension in patients undergoing radical prostatectomy

This study evaluated the effects of sodium nitroprusside-induced controlled hypotension on the acute phase response in patients undergoing radical prostatectomy. Thirty patients were randomly allocated to two groups, a hypotension group (mean arterial blood pressure was adjusted to 50 mmHg) and a control group (mean arterial blood pressure > 70 mmHg). C-reactive protein increased significantly in the hypotension group from 0.13 (0.23) to 9.85 (2.84) microg x ml-1 and in the control group from 0.15 (0.27) to 7.38 (3.02) microg x ml-1. In both groups, serum amyloid A increased significantly, but levels were higher in the hypotension group [585 (125) microg x l-1] than in the control group [460 (187) microg x l-1]. Interleukin-6 increased significantly in both groups, but was higher in the hypotension group [139 (124) pg x ml-1] than the control group [56 (27) pg x ml-1]. Elastase showed no significant changes in the control group but in the hypotension group there was a significant increase from 65 (51) to 122 (75) ng x ml-1. Sodium nitroprusside-induced hypotension was associated with a more pronounced acute phase reaction.

The effects of sodium nitroprusside-induced hypotension on splanchnic perfusion and hepatocellular integrity

The purpose of our study was to investigate the effects of sodium nitroprusside-induced hypotension on splanchnic perfusion and hepatocellular integrity. Thirty patients undergoing radical prostatectomy were allocated randomly to a sodium nitroprusside (SNP) or control group (control). Regional pco2 was measured using gastric tonometry, and the regional to arterial difference in partial pressure of CO2 and intramucosal pH were calculated. The cytosolic liver enzyme alpha-glutathione S-transferase and standard liver enzyme markers (alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase) were also measured. Mean arterial pressure in the SNP group was 50 mm Hg for 97 min during surgery. A significant increase from baseline in regional pco2 (from 40.0+/-4.2 mm Hg to 45.3+/-1.3 mm Hg) and regional to arterial difference in partial pressure of CO2 (from 4.1+/-1.1 mm Hg to 9.7+/-1.4 mm Hg) was seen at 90 min after skin incision only in the SNP group. Intramucosal pH decreased significantly from 7.40+/-0.02 to 7.35+/-0.03 during the same period in this group. Tonometric variables returned to baseline values within 2 h postoperatively. Alpha-glutathione S-transferase concentrations increased significantly in the SNP group from baseline to peak concentrations at the end of surgery (SNP: 9.93+/-4.94 microg/L; control: 5.85+/-1.86 microg/L). A return to baseline values was seen 24 h postoperatively. No significant changes in standard liver enzyme markers were seen throughout the study period. It is concluded, that splanchnic perfusion was transiently impaired during controlled hypotension. This is supported by significant changes in tonometric data. Increased serum levels of alpha-glutathione S-transferase may indicate a disturbance in hepatocellular integrity.

IMPLICATIONS

We studied gastric mucosal tonometry and the cytosolic liver enzyme alpha-glutathione S-transferase to evaluate the effects of controlled hypotension induced by sodium nitroprusside on splanchnic perfusion and hepatocellular integrity. Splanchnic perfusion decreased and alpha-glutathione S-transferase increased during and after a hypotensive period, but returned to baseline values within the first postoperative day, indicating a transient impairment of splanchnic perfusion and hepatocellular integrity.

Comparison of the effects of desflurane and isoflurane anaesthesia on hepatocellular function assessed by alpha glutathione S-transferase

The purpose of this study was to investigate the influence of isoflurane and desflurane on hepatocellular function. Twenty male patients undergoing elective surgery were randomly assigned to receive either isoflurane or desflurane anaesthesia. Alpha glutathione S-transferase concentrations and aminotransferase activities were measured at induction of anaesthesia (t0), 15 min (t1), 90 min after induction (t2), end of surgery (t3) and 2 h thereafter (t4). A significant increase in alpha glutathione S-transferase concentration was observed only in the isoflurane group. Alpha glutathione S-transferase levels increased significantly from 2.3 microg.l-1 at t0 to 6.1 (1.9) microg.l-1 at t2 and to 7.8 (2.1) microg.l-1 at t3. A significant difference in alpha glutathione S-transferase concentration between the two groups was found at t2 and t3. The significant increases in alpha glutathione S-transferase concentrations in patients receiving isoflurane suggest a transient disturbance of hepatocellular function.

Nefopam and clonidine in the prevention of postanaesthetic shivering

Postanaesthetic shivering affects up to 70% of patients after general anaesthesia, and may be very distressing. Various drugs have been used to treat or prevent postanaesthetic shivering, but the ideal one has not yet been found. Sixty patients undergoing elective abdominal or orthopaedic surgery under general anaesthesia were included in a randomised, double-blind study. Patients received clonidine (3 microgram.kg-1), nefopam (0.15 mg.kg-1) or saline 0.9% as a placebo at the end of surgery, prior to extubation. Nefopam and clonidine significantly reduced the incidence and severity of shivering in comparison with the placebo. The recovery time, between the end of anaesthesia and extubation, was significantly longer in the clonidine-treated patients [13.6 (5.2) min] than in either the nefopam [9.6 (2.8) min] or the placebo [10.0 (5.4) min] groups. Mean arterial blood pressure and heart rate were significantly lower in the clonidine group compared with both other groups. Our results suggest that nefopam and clonidine are effective in the prevention of postanaesthetic shivering. However, following clonidine administration the recovery time was prolonged and hypotension was significantly greater than after nefopam.

[Prevention of postoperative nausea and vomiting after hysterectomy with oral dolasetron, intravenous dehydrobenzperidol or a combination of both substances]

OBJECTIVE

PONV is a frequent postoperative complication. The aim of this study was to assess the efficacy of oral dolasetron in comparison to intravenous droperidol (DHB) and to a combination of both drugs for prophylaxis of PONV.

METHODS

80 patients (ASA I-III) were randomly allocated to one of four groups and received the following medication: group A: 50 mg dolasetron was given orally 45-60 minutes before anaesthesia was induced, group B: 2.5 mg i.v. DHB + placebo p.o. was administered while inducing anaesthesia (positive control group), group C: 50 mg dolasetron was given 45-60 minutes before anaesthesia was induced and 2.5 mg i.v. DHB was given while inducing anaesthesia, group D: placebo tablet was administered 45-60 minutes before anaesthesia was induced (negative control group). PONV was assessed using a 5-point score: 0 = no symptoms, 1 = nausea, 2 = retching, 3 = vomiting, 4 = multiple vomiting. Metoclopramid was given as antiemetic if a patient reached two or more score points.

RESULTS

PONV scores were significantly lower in group A and C (p < 0.001) compared to the control group. Patients treated with DHB showed a significantly lower PONV score in comparison to the placebo treated patients (p < 0.05). Between the groups A, B and C we found no significantly different PONV scores. Postoperative consumption of metoclopramid was significantly lower in the groups A (2.4 +/- 5.2 mg) and C (1.0 +/- 3.1 mg) than in the placebo group (6.0 +/- 6.8 mg), whereas between group B (3.0 +/- 5.7 mg) and D we found no significant differences.

CONCLUSIONS

Single dose of oral dolasetron and single dose of intravenous DHB reduced PONV effectively, in patients undergoing gynaecologic surgery. A combination of dolasetron and DHB has no better effect than a single dose of oral dolasetron. Contrary to DHB the application of dolasetron decreased the postoperative antiemetic requirement significantly.

The anconeus muscle flap: its anatomy and clinical application

The arterial anatomy, coverage area, and potential donor site morbidity of the anconeus muscle flap are described. Using 17 cadaveric upper extremities, we investigated the muscle's arterial anatomy in 12 specimens and defined the coverage area of the anconeus flap in 5 specimens. We also reviewed the records of 9 patients who underwent a pedicle anconeus muscle flap for elbow coverage to assess clinical results of the procedure. The anconeus muscle is supplied from 3 arterial pedicles: the recurrent posterior interosseus artery, the medial collateral artery, and the posterior branch of the radial collateral artery. The recurrent posterior interosseus artery and the medial collateral artery were present in all dissected cadavers and consistently anastomosed with each other underneath the anconeus muscle. By harvesting the muscle on the medial collateral artery, the anconeus muscle flap can be expected to cover a 7.3 cm2 defect over the radiocapitellar joint, a 6.1 cm2 defect over the distal triceps tendon, and a 7.2 cm2 defect over the olecranon. In this series, none of the patients experienced loss of elbow motion, stability, or extension strength. The results of this study indicate that the anconeus can be harvested with minimal risk of morbidity and provides effective coverage for soft tissue defects of the elbow.

[Neurologic symptoms in acute thoracic aortic dissection--a case report]

Acute thoracic aortic dissection is a life-threatening illness. It is often difficult to diagnose preclinically due to its many possible symptoms. One out of three patients has neurological deficits. The prognosis depends on rapid diagnosis and immediate adequate therapy. Therefore, every emergency physician should know the signs and risk factors of this disease. The most important goals of prehospital therapy are management of pain and anxiety and pharmacological control of the systolic blood pressure and heart rate. We report on a 46-year-old female patient who developed neurological deficits caused by an acute thoracic aortic dissection.

[Prophylactic nefopam administration for post-anesthetic shivering]

PURPOSE

Shivering is a frequent postanaesthetic complication. Its definite reason is unknown. Patients with cardiovascular or pulmonary diseases are endangered by postanaesthetic shivering. The aim of this study was to assess the efficacy of nefopam in prophylaxis of shivering. Additionally we investigated the influence of nefopam on haemodynamic parameters and on the time until extubation.

METHODS

30 patients (ASA I-II) were randomly allocated in a double-blind fashion to one of two groups to receive directly after the end of isoflurane application either nefopam (0.15 mg/kg) or placebo (0.9% saline). The period of anaesthesia had to be longer than 60 minutes. All patients received a premedication with lorazepam (0.02 mg/kg) 30-45 minutes prior to surgery. Induction of anaesthesia was standardised: fentanyl (3 micrograms/kg), thiopentone (5 mg/kg), atracurium (0.4 mg/kg). Intraoperatively a mixture of isoflurane, nitrous oxide (60%) and oxygen was used to maintain anaesthesia. The following parameters were evaluated: Age, sex, duration of operation and anaesthesia and the time between the end of application of volatiles and extubation. Heart rate (HR), mean arterial blood pressure (MAP), rectal temperature and O2-saturation were measured at predefined data points. Postoperatively the consumption of analgesic was documented. The severity of shivering was classified in five grades.

RESULTS

In the control-group nine patients shivered (60%), whereas in the nefopam group only one patient (6.6%) shivered (p < 0.05). In comparison to the placebo group we observed in the nefopam group a significantly decreased HR 30 and 60 minutes postoperatively (p < or = 0.007 and p < or = 0.002). We did not observe prolonged awakening in the nefopam-treated patients. MAP and O2-saturation showed similar reactions in both groups.

CONCLUSION

The data indicate that prophylactic administration of nefopam can suppress postanaesthetic shivering. Prolonged awakening was not observed.

Pyogenic flexor tenosynovitis

The clinical features of an infected finger flexor tendon sheath have changed dramatically since the pre-antibiotic time of Kanavel. The hand surgeon is encountering increasing numbers of gram-negative and mixed organism infections, especially in immunocompromised patients or those with comorbidities such as diabetes mellitus. The prognosis is directly related to the early recognition of the disease process and prompt surgical drainage and sheath irrigation, in combination with an appropriate antibiotic regimen. Despite appropriate management, some patients still develop significant complications. This possibility must be particularly recognized in diabetic and immunocompromised patient populations.

The effects of platelet-derived growth factor-BB on healing of the rabbit medial collateral ligament. An in vivo study

We report a biologic approach to improve medial collateral ligament healing using growth factors normally expressed in healing tissue. Our previous in vitro work demonstrated that platelet-derived growth factor-BB and transforming growth factor-beta 1 promoted fibroblast proliferation and matrix synthesis, respectively. There-fore, these growth factors were used in vivo to determine whether they could improve medial collateral ligament healing, whether this effect was dose-dependent, and if combinations of growth factors could improve healing more than individual growth factors. Thirty-seven rabbits had various doses of growth factors applied to the ruptured right medial collateral ligaments using a fibrin sealant delivery vehicle. The five groups consisted of 1) two groups receiving two doses of platelet-derived growth factor-BB, 2) two groups receiving two doses of this growth factor plus transforming growth factor-beta 1, and 3) one group receiving fibrin sealant only. After sacrifice at 6 weeks, biomechanical and histologic evaluations of the healing ligament were performed. Femur-medial collateral ligament-tibia complexes of the knees given the higher dose of platelet-derived growth factor-BB had ultimate load, energy absorbed to failure, and ultimate elongation values that were 1.6, 2.4, and 1.6 times greater than the same complexes of the control group. Adding transforming growth factor-beta 1 did not lead to any further increase in the structural properties of the complex compared with treatment with platelet-derived growth factor-BB. These encouraging results suggest that use of platelet-derived growth factor-BB may improve the quality of the healing medial collateral ligament, and that it may also have a similar potential for promoting healing of other ligaments.

Ulnar ray deficiency

Longitudinal deficiencies of the ulna are very rare deformities. Despite the cosmetic appearance, patients usually have very functional extremities. The limb function has been adversely related to ipsilateral hand deformities and radiohumeral synostosis. Surgical treatment should be aimed at correcting such deformities. It is prudent to wait and observe patients before definitive wrist or forearm treatment is recommended.

Who decides the law of the land?

A cornerstone of American-Indian cultures is a deep sense of interconnectedness with the natural environment. To preserve this sense of interconnectedness on tribal lands, many American Indians believe that sovereignty over environmental affairs on tribal lands is essential. But a number of shortcomings have historically and continually weakened tribal authority, and years of federal neglect have left most tribes unprepared to deal with their environmental problems.

Effect of partial laceration on the structural properties of the canine FDP tendon: an in vitro study

The appropriate management of partially lacerated digital flexor tendons in zone 2 is controversial. Tenorrhaphy has been advocated by some on the basis of improving tendon gliding function, whereas others have recommended foregoing tenorrhaphy because of the negative impact of repair on the tensile strength of the tendon. In light of this division, we undertook a study of the effect of varying degrees of partial laceration on the structural properties of the canine flexor digitorum profundus tendon. Lacerations up to 90% of the tendon cross-sectional area were surgically fashioned. We conclude that the structural properties of the tendon are increasingly adversely affected as laceration size increases. However, based on previous estimates of in vivo forces, even tendons with up to 60% cross-sectional area involvement may be strong enough to withstand an early active mobilization regimen. Further, we conclude that neither calipers nor naked-eye estimates provide a reliable means of assessing the extent of tendon laceration.

Healing of the medial collateral ligament after a combined medial collateral and anterior cruciate ligament injury and reconstruction of the anterior cruciate ligament: comparison of repair and nonrepair of medial collateral ligament tears in rabbits

The optimal treatment for a combined injury of the medial collateral and anterior cruciate ligaments is controversial, and the question remains as to whether repair of the medial collateral ligament and reconstruction of the anterior cruciate ligament improves healing of the medial collateral ligament. We compared reconstruction of the anterior cruciate ligament with and without repair of the medial collateral ligament in a rabbit model of a combined injury of these two ligaments. The anterior-posterior translation and varus-valgus rotation of the knee, the structural properties of the femur-medial collateral ligament-tibia complex, and the mechanical properties of the midsubstance of the medial collateral ligament were evaluated immediately after surgery and at 6 and 12 weeks postoperatively. Repair of the medial collateral ligament led to significantly less varus-valgus rotation of the knee than did no repair, but the anterior-posterior translation of the knees in the repair and nonrepair groups were not significantly different at any study time. At 12 weeks, the cross-sectional area and ultimate load in the repair group were 60 and 53% greater, respectively, than in the nonrepair group. Among 12 specimens that were repaired (six specimens at 6 weeks and six specimens at 12 weeks), failure occurred within the midsubstance in four (two at each time period); in all of the specimens that were not repaired, failure occurred at the tibial insertion site. There was no significant difference between the modulus of the modulus of the midsubstance in the repaired and the nonrepaired medial collateral ligaments.(ABSTRACT TRUNCATED AT 250 WORDS)