Morphometry of the semitendinosus and gracilis tendons with application to anterior cruciate ligament reconstruction

Anthropometric Measurements of Hamstring Tendon Graft and Its Predictors in Ligament Reconstruction Surgeries of Knee: An Observational Study

Introduction Hamstring graft use has been in the forefront of ligament reconstruction around the knee. With the increasing number of surgeries, the complications are equally on the rise. One of the detrimental factors for predicting the outcome is the diameter and length of the graft. We did an observational study to find out the relationship of patient factors with the morphometry of the graft.

Materials and Methods Total 484 patients were included in the study. Preoperatively, the age, sex, height, weight, and activity levels of the patients were noted. They were categorized into two major groups: physically active and inactive. The intraoperative measurements of the grafts were recorded. Analysis of variance for comparing the means of multiple groups was used for statistical analysis.

Results Among the total 484 patients, 407 were male and 77 were female. The semitendinosus graft diameter did not show any statistical significance to the age and weight of the patient. The mean graft diameter was highest in the 45 to 49-year age group. The average graft diameter in physically active group was 3.704 mm, and 3.503 mm in the inactive group. This and the height of the patient proved to have statistically significant relation with graft diameter.

Conclusion Physical activity along with the height of the patient must be taken into due consideration before embarking upon ligament reconstruction with hamstring graft in mind, as these two are found to determine the diameter and length of the hamstring graft.

Dimensions of pes anserinus of the lower extremity, an anatomical study with its surgical implications

The reconstructive surgeries utilize pes anserinus (PA) tendons, because of their lesser post-operative clinical deficits and donor site morbidity. These surgeries require anatomical knowledge about the extent of PA formation. The goal of this study was to determine the length and width of the PA formation. The objectives were to measure the distance of its upper limit, lower limit, and vertical distance from the tibial tuberosity (TT). The present descriptive cross sectional study included 53 embalmed cadaveric lower extremities. The upper and lower limits of PA were exposed with the careful dissection. Measurements of the dimensions were performed with the help of a digital vernier caliper (Mitutoyo Co., Kanagawa, Japan). The PA length, width, distance of its upper limit, lower limit, and vertical distance of it from the TT were 47.4±13.3 mm, 37.3±7.2 mm, 47.6±12.5 mm, 54.6±10.4 mm, and 39.1±14.2 mm, respectively over the right extremity. The same measurements were 46.3±14.7 mm, 39.1±9.4 mm, 39.1±5.9 mm, 49.5±8.2 mm, and 36.4±12.1 mm, respectively for the left extremity. The extent of PA was observed to be extremely variable. The preoperative knowledge about the dimensions of PA will help the plastic and orthopedic surgeon put the accurate skin incision, decreasing the donor site morbidity and biomechanical instability of the PA grafts. We suggest that, preoperative ultrasound measurement of the PA may help the operating surgeon to prevent the complications like injury to the infrapatellar branch of saphenous nerve.

Safety of the application of Rigidfix cross-pin system via different tibial tunnels for tibial fixation during anterior cruciate ligament reconstruction

BACKGROUND

We investigate the safety of the application of the Rigidfix cross-pin system via different tibial tunnels in the tibial fixation during anterior cruciate ligament (ACL) reconstruction.

METHODS

Five adult fresh cadaver knees were fixed with the Rigidfix cross-pins in the tibial fixation site during ACL reconstruction. Two different tibial tunnel groups were established: in group A, the tunnel external aperture was placed at the 25° angle of coronal section; in group B, the tunnel external aperture was placed at the 45° angle of coronal section. The guide was placed at the plane 0.5 mm below articular facet through the tibial tunnel, with three rotation positions set at 0°, 30°, and 60° slopes. The incidences of iatrogenic injuries at tibial plateau cartilage (TPC), medial collateral ligament (MCL), and patellar tendon in three different slope angles were calculated in groups A and B and the results were analyzed by using chi square test.

RESULTS

The iatrogenic injuries at MCL, TPC, and patellar tendon could occur after the Rigidfix cross-pin system was placed 5 mm below tibial plateau cartilage for ACL reconstruction. The incidences of TPC injury (χ² = 5.662, P = 0.017) and MCL injury (P = 0.048, Fisher exact probability method) were significantly lower in group A than in group B. However, the incidence of patellar tendon injury showed no significant difference between these two groups (χ² = 0.120, P = 0.729).

CONCLUSIONS

When the Rigidfix cross-pin system is used for ACL reconstruction at the tibial fixation site, the external aperture of tibial tunnel should not be placed at the excessively posterosuperior site, to avoid MCL and TPC injuries.

Gracilis musculotendinous free flap for lower extremity reconstruction after surgical removal of malignant tumors: A report of five cases

BACKGROUND

Lower extremity reconstruction is challenging because of the need to restore form and function. Despite the many options for soft-tissue coverage, little research has addressed combined tendon and soft-tissue reconstitution. We present a series of patients undergoing lower extremity tendon reconstruction and wound coverage with a single free gracilis flap and its tendon.

METHODS

We studied five patients (age range, 51-81 years) undergoing lower limb reconstruction for defects involving soft tissue and tendon between 1998 and 2016 in the senior author's practice. Wounds (all in the foot and ankle region) were caused by sarcoma (n = 4) and Merkel cell carcinoma (n = 1) and ranged from 6.5-10 × 8-12 cm. Donor tendons, 2-18 cm long, were used to reconstruct the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and extensor retinaculum. Patient characteristics and outcomes were reviewed retrospectively.

RESULTS

Reconstructions used a gracilis muscle free flap and its tendon. Flap sizes ranged 5-6.5 × 11-14 cm. Complications were one case of cellulitis and one case of reoperation for flap thinning and tenolysis. All patients had at least 7 months of follow-up (mean: 37 months; range: 7-104 months). At latest follow-up, all patients were ambulatory. On average, patients resumed assisted ambulation 27 days postoperatively and unassisted ambulation 62 days postoperatively.

CONCLUSIONS

For complex wounds with soft-tissue and tendinous defects, the gracilis muscle free flap may be a reconstructive option. We recommend it be considered as a single-donor incision option for lower extremity reconstruction.

Morphometric study of the semitendinosus muscle and its neurovascular pedicles in South Indian cadavers

The purpose of this study was to determine the length of the semitendinosus muscle belly and its tendon in South Indian population and to study the topography and diameter of its neurovascular pedicles. The study included 46 formalin fixed human cadaveric lower limbs. The length of the semitendinosus muscle belly and its tendon were measured. The neurovascular pedicles of the semitendinosus muscle were identified and counted. The diameter of the neurovascular pedicle was measured just before its entrance into the semitendinosus muscle. The topographical distance of the neurovascular pedicles from the origin of the semitendinosus muscle were determined. The mean length of the semitendinosus muscle belly was 332.3±36.1 mm and its tendon measured 154.8±31.9 mm. The mean diameter of the vascular pedicle was measuring 11.4±9.1 mm, just before its entrance into the semitendinosus muscle. The neurovascular pedicles, of the semitendinosus muscle were ranging between 1 and 7. The distance of the entrance of neurovascular pedicle to the semitendinosus muscle from its origin was ranging between 46 and 272 mm. It was observed that the neurovascular pedicles were highest (31%) at the range of 151-200 mm away from the ischial tuberosity. The morphometric data obtained in the present study is enlightening to the orthopedic and plastic surgeons. The topographical knowledge of the neurovascular pedicles has its implications during the harvesting of the grafts and pedicle flaps. The diameter of vessels in the pedicles is enlightening because of new method of anterior cruciate ligament reconstruction.

A 3-Dimensional Anatomic Study of the Distal Biceps Tendon: Implications for Surgical Repair and Reconstruction

BACKGROUND

Complete rupture of the distal biceps tendon from its osseous attachment is most often treated with operative intervention. Knowledge of the overall tendon morphology as well as the orientation of the collagenous fibers throughout the musculotendinous junction are key to intraoperative decision making and surgical technique in both the acute and chronic setting. Unfortunately, there is little information available in the literature.

PURPOSE

To comprehensively describe the morphology of the distal biceps tendon.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The distal biceps terminal musculature, musculotendinous junction, and tendon were digitized in 10 cadaveric specimens and data reconstructed using 3-dimensional modeling.

RESULTS

The average length, width, and thickness of the external distal biceps tendon were found to be 63.0, 6.0, and 3.0 mm, respectively. A unique expansion of the tendon fibers within the distal muscle was characterized, creating a thick collagenous network along the central component between the long and short heads.

CONCLUSION

This study documents the morphologic parameters of the native distal biceps tendon. Reconstruction may be necessary, especially in chronic distal biceps tendon ruptures, if the remaining tendon morphology is significantly compromised compared with the native distal biceps tendon. Knowledge of normal anatomical distal biceps tendon parameters may also guide the selection of a substitute graft with similar morphological characteristics.

CLINICAL RELEVANCE

A thorough description of distal biceps tendon morphology is important to guide intraoperative decision making between primary repair and reconstruction and to better select the most appropriate graft. The detailed description of the tendinous expansion into the muscle may provide insight into better graft-weaving and suture-grasping techniques to maximize proximal graft incorporation.

Anatomic reconstruction of the medial patellofemoral ligament using the fascia lata as an autograft

The medial patellofemoral ligament (MPFL) ensures stability of the patella against lateral forces. In cases of recurrent lateral patellar luxation, surgical reconstruction of the MPFL has an important role in treating lateral patellar instability. Several biomechanical studies have presented valuable pieces of information about various techniques for re-creating this medial patellofemoral complex mainly using the gracilis tendon as an autograft. However, with the increasing number of MPFL reconstructions, there are also an increasing number of patients requiring revision MPFL reconstruction. Therefore alternative graft options may become more relevant. Furthermore, the gracilis tendon as a tubular graft may not be able to fully restore patellofemoral kinematics compared with the native MPFL. This article introduces a surgical technique using the fascia lata as an alternative graft option for the anatomic reconstruction of the MPFL.

Can the gracilis be used to replace the anterior cruciate ligament in the knee? A cadaver study

PURPOSE

The purpose of this study was to evaluate whether a four-strand gracilis-only graft can be used in anterior cruciate ligament (ACL) reconstruction.

STUDY DESIGN

Cadaver study.

METHODS

This study involved 16 cadaver knees. The length and diameter of the native ACL were measured in each one. The same measurements were performed on a four-strand graft of the gracilis only, the semitendinosus only and both tendons. Student's t-test was used to compare the various conditions.

RESULTS

The average diameter of the G4 construct was 0.07 mm greater (1%) than the native ACL (p=0.044). The average cross-sectional area of the G4 construct was 1.2 mm(2) greater (3.9%) than the native ACL (p=0.049). The G4 was on average 38.9 mm longer than the intra-articular portion of the ACL (p<0.001).

CONCLUSION

A four-strand gracilis construct meets the anatomical specifications for use as an ACL reconstruction graft. By using the gracilis only, the morbidity associated with harvesting the gracilis and semitendinosus tendons should be reduced. Further studies must be performed to compare the biomechanical properties of this graft with other graft types and also to evaluate how this four-strand gracilis graft behaves in a clinical setting.

Minimally invasive medial patellofemoral ligament reconstruction with fascia lata allograft: surgical technique

The present paper describes a new minimally invasive anatomic medial patellofemoral ligament reconstruction, using a fascia lata allograft as graft source and arthroscopy to obtain balanced fixation throughout the range of motion.

Medial patellofemoral ligament reconstruction: the superficial quad technique

BACKGROUND

Medial patellofemoral ligament (MPFL) reconstruction is a routine procedure for patellar instability. The majority of the techniques require hardware fixation or a bony procedure at the patella. However, most of the complications described in the literature can be attributed to patellar fixation. The "superficial quad technique" uses the superficial slip of the quadriceps tendon as the graft material, which provides a better anatomic match to the native MPFL.

HYPOTHESIS

The superficial quad technique provides anatomic patellar fixation without a bony procedure and without patellar complications.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The study included 32 patients (10 male, 22 female; mean age, 25 years) who underwent MPFL reconstruction using the superficial quad technique and who were followed for a mean duration of 38 months. Objective assessment was performed and Kujala scores were obtained preoperatively and at the time of final follow-up.

RESULTS

There were no patellar complications, including redislocation, in the present study. The mean Kujala score improved to 91.25 (range, 73-100) from a preoperative score of 49.31 (range, 23-62).

CONCLUSION

The results were comparable with those of other studies in the literature that used hamstring grafts, but without associated patellar complications. The superficial quad technique uses graft material that is a better anatomic match to the native MPFL. It provides anatomic patellar fixation without a bony procedure.

In vivo and in vitro examination of the tendinous inscription of the human semitendinosus muscle

The aim of this study was to examine the tendinous inscription (TI) of the human semitendinosus (ST) muscle using dissection (cadavers) and ultrasound (in vivo). Ultrasonography (US) scans were taken in 18 young males at rest and at maximum voluntary contraction (MVC). Further, the ST was dissected and removed from its origins in 10 cadaveric specimens (5 cadavers). The cadaveric long arm of the TI was 6.67 ± 0.64 cm (6.45 ± 1.21 in US) while the shorter arm was 2.39 ± 0.38 cm (1.99 ± 0.75 in US). The angle formed by the two TI arms ranged from 53.19 (US) to 56.05° (cadavers) while more superficial fascicles intersected the inscription at significantly higher angles (range 31.98 ± 6.15 to 34.69 ± 7.71°) compared with deeper fascicles (p < 0.05). Fascicle length did not differ between compartments, but it was significantly smaller in superficial compared with deeper layers (p < 0.05). With the exception of the angle between the TI arm and the deep aponeurosis, all measured angles as well as the length of the long arm of the TI increased significantly from rest to MVC (p < 0.05). The role of the TI probably lies in the local interconnections with the fascicles of either compartment, which upon contraction is such that the ST muscle contracts as one muscle. However, the TI arm morphology changes from rest to MVC, indicating a nonuniform displacement of the TI, mainly between the superficial and deeper layers of the muscle.

Differences in length and cross-section of semitendinosus and gracilis tendons and their effect on anterior cruciate ligament reconstruction

The purpose of this anatomical study was to explore the morphological variations of the semitendinosus and gracilis tendons in length and cross-section and the statistical relationship between length, cross-section, and body height.

We studied the legs of 93 humans in 136 cadavers. In 43 specimens (46.2%) it was possible to harvest the tendons from both legs.

We found considerable differences in the length and cross-section of the semitendinosus and the gracilis tendons with a significant correlation between the two. A correlation between the length of the femur, reflecting height, and the length of the tendons was only observed in specimens harvested from women. The reason for this gender difference was unclear. Additionally, there was a correlation between the cross-sectional area of the tendons and the length of the femur. Surgeons should be aware of the possibility of encountering insufficient length of tendon when undertaking reconstructive surgery as a result of anatomical variations between patients.

Biomechanical analysis of medial collateral ligament reconstruction grafts of the elbow

BACKGROUND

There are no biomechanical studies evaluating different tendon grafts for elbow medial collateral ligament reconstruction.

HYPOTHESIS

Using a larger tendon for the graft will yield greater resistance to valgus load for medial collateral ligament docking technique reconstructions. The type of graft used for a medial collateral ligament docking technique reconstruction will have a significant effect on the resistance to valgus loads.

STUDY DESIGN

Controlled laboratory study.

METHODS

Cadaveric elbows from male donors were cyclically loaded to 3 and 5 mm elongation, both intact and after a docking technique medial collateral ligament reconstruction using palmaris longus, gracilis, semitendinosus, and patellar tendon grafts.

RESULTS

There was no significant difference in load to 3 or 5 mm elongation, number of cycles to failure, or stiffness between any tendon graft studied. Every tendon graft reconstruction tested was significantly weaker and less stiff than was the native medial collateral ligament.

CONCLUSION

There appears to be no biomechanical advantage to be gained by using a larger tendon graft instead of a palmaris longus graft.

CLINICAL RELEVANCE

The most readily available graft source with the lowest morbidity (often the palmaris longus tendon) should be used for medial collateral ligament reconstruction.

Comparison between the cross-sectional area of bone-patellar tendon-bone grafts and multistranded hamstring tendon grafts obtained from the same patients

This study intraoperatively compared the cross-sectional area (CSA) and graft-tunnel fit of bone-patellar tendon-bone (BTB) and multistranded hamstring tendon (STG) grafts harvested from the same patient. Twenty-two patients with a mean age of 26 years were the subjects of the study. Each BTB graft was harvested from the central third of the patellar tendon. Tripled or quadrupled semitendinosus tendon with or without gracilis tendon was used as a STG graft. CSAs of both grafts in the same patients were intraoperatively measured using a custom-made area micrometer during primary ACL reconstruction and revision surgery or during combined ACL and PCL reconstruction. Graft-tunnel fit was calculated by dividing the CSA of the graft by that of the tibial bone tunnel. The average CSA of STG grafts was significantly greater than that of BTB grafts. The average value of graft-tunnel fit for the STG grafts% was also greater than that of the BTB grafts%. Thus STG grafts have a larger CSA and closer graft-tunnel fit than BTB grafts in a clinical setting.

Semitendinosus muscle in anterior cruciate ligament surgery: Morphology and function

PURPOSE

To evaluate the fate of the hamstring muscles in general and the semitendinosus muscle in particular, after anterior cruciate ligament (ACL) reconstruction with an autologous semitendinosus tendon graft from the ipsilateral side.

TYPE OF STUDY

Prospective consecutive case series investigation.

METHODS

Included were 16 consecutive patients, 14 male and 2 female, with a mean age of 26 years. The inclusion criterion was chronic unilateral ACL insufficiency with no concomitant knee ligament injuries. ACL reconstruction was performed with a quadruple semitendinosus tendon graft using the EndoButton technique (Acufex, Mansfield, MA). Intraoperatively, muscle specimens were taken from the semitendinosus muscle on the harvested side. Follow-up at a minimum of 6 months included clinical examination, isokinetic strength performance, magnetic resonance imaging (MRI) of the thigh and knee, and ultrasound-guided muscle biopsy procurement from the semitendinosus muscle for histochemical and enzymatic analyses.

RESULTS

Of the patients, 75% showed regeneration of their semitendinosus tendons. The neotendons all inserted below the knee joint where they had fused with the gracilis tendon to a conjoined tendon inserting in the pes anserinus. The semitendinosus muscle had a smaller cross-sectional area on the operated side but none showed total atrophy. Less atrophy was present in the patients with a regenerated semitendinosus neotendon compared with those without regeneration (P =.029). In the latter group the semimembranosus muscle seemed to compensate for this with hypertrophy (P =.019). Cross-sectional muscle fiber areas, the relative number of each fiber type and oxidative potential as estimated by citrate synthase activity, showed no significant differences between the operated and nonoperated legs. The isokinetic strength of the hamstrings and quadriceps was significantly lower in the operated leg than in the nonoperated leg.

CONCLUSIONS

With this surgical technique, the semitendinosus muscle can recover and the tendon has, according to the MRI images, a great potential to regenerate after its removal.

Patellar versus hamstring tendons in anterior cruciate ligament reconstruction: A meta-analysis

PURPOSE: To compare the outcome of ACL reconstuction using patellar tendon (PAT) to that when using hamstring tendons. Type of Study: Meta-analysis of controlled trials of patellar tendon versus hamstring tendons for ACL reconstruction. METHODS: Meta-analysis is a systematic method for statistical analyses that allows compilation of combined data from various independent studies. This allows one to assess the potential benefits of various treatments when conclusions based on individual studies are difficult to assess. We conducted a meta-analyses (M-A) using controlled trials (CTs) to determine if there are differences between the 2 methods. Although both surgical techniques have potential for good results, we hypothesized that there are differences in outcomes between these techniques. We included CTs that used standard evaluation techniques with a minimum 2-year follow-up. Outcomes evaluated included: return to preinjury level of activity, KT testing, Lachman scores, pivot shift scores, range of motion (ROM) loss in flexion and extension, complications, and failures. Relative risks for each outcome were calculated for each study and pooled across studies using a fixed effects method. RESULTS: Four studies fulfilled our inclusion criteria. Relative risks with 95% confidence intervals and P values were obtained for each of the outcomes listed above. The results show significant differences between PAT and semitendinosus and gracilis tendon (ST&G) reconstructions. PAT patients have a greater chance of attaining a statically stable knee (as measured by KT) and nearly a 20% greater chance of returning to preinjury activity levels. CONCLUSIONS: Although both techniques, as performed in the late 1980s and early 1990s, yielded good results, PAT reconstuction led to higher postoperative activity levels and greater static stability than hamstring reconstruction. This is statistically significant based on this meta-analysis.

Multiple-component tissue reconstruction of a complex dorsal foot wound through a single gracilis muscle donor incision

The authors describe the ability of the gracilis muscle to provide multiple tissue components- skin, muscle, nerve, and tendonin the reconstruction of a complex dorsal foot wound resulting from a sarcoma resection. The deficits of skin, deep peroneal nerve, anterior tibialis tendon, and dorsal extensor retinaculum were all reconstructed with the gracilis component flap through one medial thigh incision. This case illustrates two important points: (1) the gracilis flap is tremendously versatile and can serve as the donor for multiple tissue components in complex reconstructions, and (2) donor site morbidity can and should be minimized even in complex reconstructions.

The effect of screw insertion torque on tendons fixed with spiked washers

The long-term success of a hamstring tendon graft depends not only on the type of device that is used for fixation but also on the mechanical interlocking of the soft tissue between the fixation device and bone. The purpose of this study was to evaluate the effect of screw insertion torque on the structural properties of soft tissue fixed to bone with a spiked metal washer. Two bovine tendons, one similar in size to a human semitendinosus tendon and the other similar in size to a human gracilis tendon, were secured to a bovine femur using a figure-of-8 technique with screws and metal spiked washers. A single load to failure was applied at 25 mm/sec. A significant positive linear correlation was observed between fixation screw insertion torque magnitude and the ultimate failure load value. An increase in the fixation screw insertion torque produced an increase in the ultimate failure load value. Similarly, there was a significant positive linear correlation between fixation screw insertion torque magnitude and the average maximum linear load value. No relationship was detected between screw insertion torque magnitude and the linear stiffness values of the tendon-fixation construct, indicating that a reproducible model was used. This study demonstrates that screw insertion torque is an important variable that controls the initial strength of soft tissue fixation to bone.