Purpose:
This experimental study investigated the long head biceps tendon (LHBT) excursion that occurs at various positions of the upper limb during tendon stabilizing procedures. We hypothesized ...that shoulder abduction, elbow extension and forearm pronation would maximize the excursion of the LHBT and potential impacts on tendon stabilization.
Materials & Methods:
Forequarter specimens from 12 fresh frozen cadavers were used in this study. The study was performed at 0° and 30° of shoulder abduction. Elbow position was either 90° of flexion or full extension with the forearm either in full pronation or supination. A total of 14 combinations of positions were studied. A load of 55 N was applied to the distal biceps. The excursion of the proximal part of LHBT was measured for each of the different positions.
Results:
At a shoulder position of 30° of flexion, shoulder abduction of 30° created significantly greater excursion than 0° of shoulder abduction (p < 0.001). Both full extension of the elbow and full pronation of the forearm also showed significant excursion of the tendon when compared to supination (p < 0.001).
Conclusions:
The position of the shoulder, elbow and forearm has a significant effect on biceps excursion. Thirty degrees of shoulder abduction and 30° of forward flexion with the elbow in full extension and the forearm in full pronation maximizes excursion.
Clinical Relevance:
Information about the excursion of the LHBT affected by the position of the upper limb is useful for any biceps tendon stabilizing procedure. During an operation, the position of the upper limb should be monitored in order to maintain a proper anatomic length-tension relationship.
Background:
Operative treatment is suggested for unstable type 3 acromioclavicular (AC) joint injuries; however, there is no clear consensus regarding the definition of an unstable type 3 injury. We ...propose a new radiographic method, the “Chiang Mai lean forward” view, to verify horizontal displacement in an unstable AC joint injury.
Hypothesis:
A radiograph taken with the torso leaning forward would allow the detection of a higher proportion of AC joint injuries.
Study Design:
Descriptive laboratory study.
Methods:
A total of 20 shoulders from 10 fresh whole-body cadaveric specimens (mean age, 68.8 years) were tested at 3 different torso leaning angles (30°, 45°, and 60°) to determine the best position for projecting the x-ray beam. The shoulders were dissected sequentially starting with the AC ligament (stage 1), then additional sectioning of the partial coracoclavicular (CC) ligament with either the trapezoid ligament cut first (stage 2A) or the conoid ligament cut first (stage 2B), and finally complete sectioning of the CC ligament (stage 3). Radiography was performed after each stage to evaluate the degree of displacement of the anterior border of the acromion relative to the anterior border of the clavicle. Paired t tests were used to compare the degree of displacement at each stage to that of the shoulder before cutting.
Results:
Leaning at an angle of 30° provided better visualization of the AC joint in the “Chiang Mai lean forward” view. Compared with the intact condition, complete isolated cutting of the AC ligament produced 5.21 mm of horizontal displacement of the AC joint (P < .0001), complete tearing of the AC ligament and partial cutting of the CC ligament resulted in a displacement of <12 mm (7.91 mm at stage 2A P = .0003 and 8.10 mm at stage 2B P = .0013), and complete tearing of both the AC and the CC ligaments resulted in a displacement of 26.37 mm (P < .0001).
Conclusion:
The “Chiang Mai lean forward” radiographic view is a potentially useful tool for determining the degree of the injury and the stability of the AC joint.
The effect of glenoid version on the severity of glenoid bone loss is not completely understood, although the variation of glenoid version angles is considered to reflect the degree of glenoid bone ...loss in anterior shoulder instability cases. The objective of this retrospective case-control study is to determine the relationship of the glenoid version and the severity of glenoid bone loss in a group of previously documented recurrent anterior shoulder dislocation patients.
We retrospectively collected magnetic resonance arthrogram (MRA) data from 72 patients with unidirectional recurrent anterior shoulder instability. The best-fit circle method was used to identify the percentage of glenoid bone loss. Measurements of glenoid labral, chondral, and bony versions were performed using the Friedman method.
Using univariate regression analysis, it was found that a retroversion angle of more than 4 degrees was associated with an increased risk ratio for the occurrence of a critical glenoid defect by approximately 5 times.
24 Univariate logistic regression analysis, used to determine the presence of a critical glenoid bone defect, showed that both the bony version angle and the number of previous dislocations were significantly associated with the extent of glenoid bone loss. A retroversion angle of more than 4 degrees was associated with an approximately five-fold increase in the odds ratio for the presence of a critical glenoid defect. Surgeons may use the value of the measured glenoid version in prediction the required version of the reconstructive treatment.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Arthroscopic Bankart repair (ABR) has become a standard treatment for recurrent anterior shoulder dislocation in cases with minimal bone loss. Using the standard Bankart repair technique, the failure ...rate has been reported to be approximately between 4 and 35%. In addition to the original injury, multiple pathologies can occur after a dislocation including a Bankart lesion, capsular redundancy and bone defects. In cases with no significant bone loss, soft tissue plays a major role in stabilizing the shoulder joint. We hypothesized that effective repair of soft tissue with good inferior capsular shifting and proper capsulolabral restoration can create a proper level of soft tissue tension so the horizontal mattress suture method should improve outcomes.
A retrospective cohort study was conducted by reviewing the records of patients with recurrent anterior instability who underwent ABR at a single institution between January 2009 and December 2017. Demographic information, preoperative radiographic data including glenoid bone loss, Hill-Sachs width, glenoid track and other surgical details were retrieved from the medical records. The patients identified were divided into 2 groups. Group 1 had one modified Mason Allen stitch plus simple stitches, while Group 2 had only simple stitches. Data obtained from the patient included failure rate, patient satisfaction, the ROWE score and Walch-Duplay score at a minimum of 2 years after surgery. Risk factors for failure were also identified.
Group 1 included 50 patients (mean age 27.2 ± 9.4 years) who underwent modified Mason Allen stitch ABR (median follow-up, 59.2 months; range, 26.2–128.6 months). Group 2 included 30 patients (mean age 26.9 ± 8.5 years) who underwent simple stitch repair ABR (median follow-up, 68.0 months; range, 24.0–127.9 months). All patients met the inclusion criteria. Evaluation at the final follow-up compared Group 1 and Group 2: ROWE score (86.8 vs 76.3, P = 0.001), Walch-Duplay score (87.2 vs 82.0, P = 0.035), respectively. Failure rates were 6% in group 1 compared to 10% in group 2 (P = 0.511).
The modified Mason Allen stitch technique and the simple stitches technique ABR both result in excellent patient satisfaction at a minimum 2-year follow-up. Both techniques successfully restore shoulder stability, but the modified Mason Allen stitch technique results in better functional outcomes.
Cohort study; level of evidence, 3.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
Suspension suture button fixation was frequently used to treat acromioclavicular joint (ACJ) dislocation. However, there were many studies reporting about complications and residual ...horizontal instability after fixation. Our study compared the stability of ACJ after fixation between coracoclavicular (CC) fixation alone and CC fixation combined with ACJ repair by using finite element analysis (FEA).
Materials and methods
A finite element model was created by using CT images from the normal shoulder. The model 1 was CC fixation with suture button alone, and the model 2 was CC fixation with suture button combined with ACJ repair. Three different forces (50, 100, 200 N) applied to the model in three planes; inferior, anterior and posterior direction load to the acromion. The von Mises stress of the implants and deformation at ACJs was recorded.
Results
The ACJ repair in the model 2 could reduce the peak stress on the implant after applying the loading forces to the acromion which the ACJ repair could reduce the peak stress of the FiberWire at suture button about 90% when compared to model 1. And, the ACJ repair could reduce the deformation of the ACJ after applying the loading forces to the acromion in both vertical and horizontal planes.
Conclusion
This FEA supports that the high-grade injuries of the ACJ should be treated with CC fixation combined with ACJ repair because this technique provides excellent stability in both vertical and horizontal planes and reduces stress to the suture button.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
One option for the treatment of type 2 superior labral anterior to posterior (SLAP) lesions is arthroscopic repair. However, the fact that the vascular supply of the proximal long head of the biceps ...tendon (LHBT) arises from the soft tissue near the SLAP repair site must also be considered. The aims of this study were to evaluate the vascular channel of the proximal long head biceps tendon and to compare potential damage to the vascular supply with alternative SLAP techniques.
Forty-five fresh cadaveric shoulders were divided into 3 groups: 9 shoulders each for the normal group and the created SLAP group, and 27 shoulders for the repaired SLAP group. SLAP group shoulders were repaired using one of 3 techniques: 2 anchors with simple sutures, 1 anchor with double sutures, or 1 anchor with a horizontal mattress suture. India ink was then injected into the acromial branch of the thoracoacromial artery. The proximal LHBT was resected for a histologic cross-sectional study. The intratendinous vascular distance was measured and compared among the groups.
The vascular supply of the proximal LHBT arises from soft tissue lying anterior and dorsal to the tendon origin. In the normal shoulders, the average intratendinous vascular distance was 16.9 ± 1.5 mm (95% confidence interval: 15.8-18.1). A comparison of nonrepaired SLAPs with each of the repair techniques found that using 2 anchors with simple sutures showed no significant difference in vascular distance (P = .716), whereas the other techniques showed a significant disruption of the blood supply. The differences in vascular distance among the 3 repair techniques were statistically significant (P = .0001).
The main vascular supply of the proximal LHBT comes from the anterior-dorsal direction. Some SLAP repair techniques can disrupt vascularization; however, the technique using 2 anchors with simple sutures, 1 anchor 3 mm anterior to the anterior border and 1 at the posterior border of the tendon, can preserve the vascularization of the LHBT.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Introduction
The selection of a surgical approach for buttressing posterolateral tibial plateau fractures is controversial.
Objective
This study compared the surgical exposure area between the ...reversed L posteromedial approach (R-PM) and the posterolateral (PL) approach using the lateral plateau width as a metric.
Materials and methods
Twenty lower extremities from fresh frozen cadavers were included. The R-PM approach was used first and the boundary of the posterior tibial cortex exposure was marked with metal pins. With the same specimens, the PL approach was then performed and the exposure area was marked. After removing all soft tissue, an imaginary line was drawn from the lateral plateau rim anterior to the fibular head (L) to the posteromedial ridge of the tibia (M). Additional metal pins were used to indicate bony reference landmarks at the joint line on the posterior tibial plateau, including the lateral tibial spine (S), the lateral boundary with the PM approach (
L
PM) and the lateral boundary with the PL approach (
L
PL). All distances were measured using S as the reference point.
Results
The average distance from S to L, referred to as the lateral plateau width (A), was 32.62 mm. The average distances from S to
L
PM (B) and from S to
L
PL measured as a percentage of A were 43.72 and 81.41%, respectively. The average R-PM approach blind distance from
L
PM to
L
PL (C) as a percentage of the lateral plateau width was 58.45%, while the distance
L
PL to L (D), which represents the invisible blind distance with both approaches, was 15.37% of that width.
Conclusions
The PL approach provides better access for buttressing the posterolateral tibial plateau fracture than the R-PM approach. With the R-PM approach, the blind area on the lateral plateau which can be accessed only by the PL approach starts approximately at 43.72% and ends at 81.41% of the lateral tibial plateau width. When a fracture is located in this zone, the posterolateral approach is recommended.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Introduction
Fixation of a small Hoffa fragment requires a selection of the proper surgical approach for reduction and posterior to anterior screws fixation. However, currently there are no ...guidelines regarding how to select the best approach for small posterior Hoffa fractures.
Objectives
To compare the size of Hoffa fractures that are appropriate for reduction and fixation with the medial parapatellar approach (MPPA) and those which require the direct medial approach (DMA), and to make a similar comparison between the lateral parapatellar approach (LPPA) and the posterolateral approach (PLA).
Materials and methods
Twenty extremities of fresh cadavers were included. After completion of each approach, the articular surface boundaries were marked and soft tissue was removed. On the medial condyle, an imaginary line was drawn from the most anterior (A) to the most posterior (B) point, representing the AP diameter (
d
3
). The most posterior boundary of MPPA (C) and the most anterior boundary of DMA (D) were similarly marked. Distances between B and C (
d
1
) and between B and D (
d
2
) were measured as well as the anterior–posterior diameter of the condyle (
d
3
). The same measurements were made for the lateral condyle.
Results
On the medial condyle, the average values of
d
1
,
d
2
, and
d
3
were 10.8 mm ± 3.8, 17.3 mm ± 3.3, and 60.1 mm ± 3.2, while percentages of
d
1
/
d
3
and
d
2
/
d
3
were 18.3% ± 6.4 and 28.7% ± 4.7. In lateral condyle, the averages for
d
1
,
d
2
,
d
3
were 6.1 mm ± 1.4, 12.1 mm ± 2.8 and 60.9 mm ± 3.3 mm and the percentages of
d
1
/
d
3
and
d
2
/
d
3
were 10.1% ± 2.3 and 19.9% ± 4.9.
Conclusions
When the Hoffa fragment is less than 18.3% of the AP diameter of medial condyle or 10.1% of lateral condyle, the fracture is invisible with the PPA. When the Hoffa fragment is more than 28.7% of the medial condyle or 19.9% of the lateral condyle, the PPA should be selected. If the Hoffa fragment is less than 28.7% of the medial condyle or 19.9% of the lateral condyle, the DMA or PLA with posterior-to-anterior screws is recommended. Combined approaches should be considered in some complex cases with articular comminution.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
BackgroundLoss of knee extension has been reported by many authors to be the most common complication following anterior cruciate ligament reconstruction. The objective of this in vitro study was to ...determine the effect, on loss of knee extension, of the knee flexion angle and the tension of the bone-patellar tendon-bone graft during graft fixation in a reconstruction of an anterior cruciate ligament.MethodsThe anterior cruciate ligament was reconstructed with use of tibial and femoral bone tunnels placed in the footprint of the native anterior cruciate ligament in ten cadavers. The graft was secured with an initial tension of either 44 N (10 lb) or 89 N (20 lb) applied with the knee at 0° or 30° of flexion. The knee flexion angle was measured with use of digital images following graft fixation.ResultsTensioning of the graft at 30° of knee flexion was associated with loss of knee extension in this cadaver model. Graft tension did not affect knee extension under the conditions tested.ConclusionsThe results suggest that one of the common causes of the loss of full knee extension may be diminished if the graft is secured in full knee extension when the tibial and femoral tunnels are placed in the footprint of the native anterior cruciate ligament. More importantly, even when the femoral and tibial tunnels are placed in the femoral and tibial footprints of the native anterior cruciate ligament, fixing a graft in knee flexion can result in the loss of knee extension.
PDF
