Lateral Translation of the Patella in MPFC Reconstruction: A Biomechanical Study of Three Surgical Techniques (210)

Objectives: Recurrent patellar instability (RPI) is a common knee disorder and can lead to chronic pain and functional disability. Surgically addressing recurrent patella instability has classically focused on reconstruction of the MPFL, which has widely become the standard of care either in isolation or concomitantly with other patellar realignment procedures. Complications following MPFL reconstruction include patellar fracture, articular surface penetration, and physeal injury in skeletally immature patients. In an effort to avoid these, other surgical techniques have been described. While these alternative MPFC reconstructions have anatomical support and the theoretical potential to reduce complications, it is unknown whether differences exist in lateral patellar translation and thus their effectiveness in adequately stabilizing the patella. The purpose of this study was to investigate whether differences exist in the ability to prevent lateral patellar translation between three distinct medial patellar stabilizing surgical procedures at varying knee flexion angles. Methods: Six cadaveric knee specimens were dissected, potted, and placed in a customized jig for testing. The quadricep muscle groups were separated into three components and loaded with a total of 175 N in anatomic directions using a weighted pulley system. Lateral patellar displacement was measured at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of knee flexion using a tensile testing machine with a 20 N lateral force applied to the patella. Each specimen was tested with the MPFC intact and sectioned, and after each of the three reconstruction techniques: medial patellofemoral ligament (MPFL) reconstruction, hybrid (proximal medial patellar restraints - PMPR) reconstruction, and medial quadriceps-tendon femoral (MQTFL) reconstruction. Statistical analysis used the Friedman and Wilcoxon rank sum tests due to non-normally distributed data. Results: There was significantly increased lateral patellar displacement following MPFC sectioning when compared to the intact state in early degrees of flexion (10° to 30°) (p<0.05). All three reconstruction groups adequately restored patella stability and reduced lateral patellar displacement following medial soft tissue sectioning by 42%, 41% and 33% following MPFL, Hybrid and MQTFL reconstruction, respectively, from 0° to 30° of knee flexion (p<0.05 for each reconstruction group). When compared to the native, intact medial restraints group, all three reconstruction groups demonstrated reduced patella translation at full knee extension, while the MPFL and Hybrid reconstruction groups additionally demonstrated significant reduction of patella translation at 10° of flexion as well (p<0.05). When comparing patella displacement between reconstruction groups, no significant difference was observed at any degrees of flexion between the three groups. Conclusions: This biomechanical cadaveric study demonstrates the efficacy of three different MPFC reconstruction techniques in restoring patella stability following MPFC sectioning, especially at lower knee flexion angles where the medial soft tissue restraints play a more important role. Although all three reconstruction groups demonstrated less patella translation than the native MPFL intact knee, MPFL reconstruction appears to provide the most robust patella stabilization, whereas MQTFL reconstruction may be the most forgiving construct. Future clinical studies are needed to investigate the clinical correlation of these findings.

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Interference Screw Versus Suture Anchors for Femoral Fixation in Medial Patellofemoral Ligament Reconstruction: A Biomechanical Study

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967121989282 ◽

2021 ◽

Vol 9 (3) ◽

pp. 232596712198928

Author(s):

Heath P. Gould ◽

Nicholas R. Delaney ◽

Brent G. Parks ◽

Roshan T. Melvani ◽

Richard Y. Hinton

Keyword(s):

Medial Patellofemoral Ligament ◽

Interference Screw ◽

Biomechanical Study ◽

Graft Fixation ◽

Mpfl Reconstruction ◽

Suture Anchors ◽

Femoral Fixation ◽

Significant Difference ◽

Load To Failure ◽

The Mean

Background: Femoral-sided graft fixation in medial patellofemoral ligament (MPFL) reconstruction is commonly performed using an interference screw (IS). However, the IS method is associated with several clinical disadvantages that may be ameliorated by the use of suture anchors (SAs) for femoral fixation. Purpose: To compare the load to failure and stiffness of SAs versus an IS for the femoral fixation of a semitendinosus autograft in MPFL reconstruction. Study Design: Controlled laboratory study. Methods: Based on a priori power analysis, a total of 6 matched pairs of cadaveric knees were included. Specimens in each pair were randomly assigned to receive either SA or IS fixation. After an appropriate reconstruction procedure, the looped end of the MPFL graft was pulled laterally at a rate of 6 mm/s until construct failure. The best-fit slope of the load-displacement curve was then used to calculate the stiffness (N/mm) in a post hoc fashion. A paired t test was used to compare the mean load to failure and the mean stiffness between groups. Results: No significant difference in load to failure was observed between the IS and the SA fixation groups (294.0 ± 61.1 vs 250.0 ± 55.9; P = .352), although the mean stiffness was significantly higher in IS specimens (34.5 ± 9.6 vs 14.7 ± 1.2; P = .004). All IS reconstructions failed by graft pullout from the femoral tunnel, whereas 5 of the 6 SA reconstructions failed by anchor pullout. Conclusion: In this biomechanical study using a cadaveric model of MPFL reconstruction, SA femoral fixation was not significantly different from IS fixation in terms of load to failure. The mean load-to-failure values for both reconstruction techniques were greater than the literature-reported values for the native MPFL. Clinical Relevance: These results suggest that SAs are a biomechanically viable alternative for femoral-sided graft fixation in MPFL reconstruction.

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Ability of Medial Patellofemoral Ligament Reconstruction to Overcome Lateral Patellar Motion in the Presence of Trochlear Flattening: A Cadaveric Biomechanical Study

The American Journal of Sports Medicine ◽

10.1177/03635465211041087 ◽

2021 ◽

pp. 036354652110410

Author(s):

Amrit V. Vinod ◽

Alex M. Hollenberg ◽

Melissa A. Kluczynski ◽

John M. Marzo

Keyword(s):

Repeated Measures ◽

Knee Flexion ◽

Medial Patellofemoral Ligament ◽

Operative Procedure ◽

Biomechanical Study ◽

Mpfl Reconstruction ◽

Trochlear Groove ◽

Sulcus Angle ◽

Fresh Frozen ◽

Patellar Stability

Background: Medial patellofemoral ligament (MPFL) reconstruction is an established operative procedure to restore medial restraining force in patients with patellar instability. In the setting of a shallow sulcus, it is unclear whether an isolated MPFL reconstruction is sufficient to restore patellofemoral stability. Hypothesis: Progressively increasing the sulcus angle would have an adverse effect on the ability of an MPFL reconstruction to restrain lateral patellar motion. Study Design: Controlled laboratory study. Methods: Seven fresh-frozen human cadaveric knees were harvested and prepared for experimentation. Each specimen was run through the following test conditions: native, lateral retinacular release, lateral retinacular repair, MPFL release, MPFL reconstruction, and MPFL reconstruction with trochlear flattening. Four 3-dimensional printed wedges (10°, 20°, 30°, and 40°) were created to insert beneath the native trochlea to raise the sulcus angle incrementally and simulate progressive trochlear flattening. For each test condition, the knee was positioned at 0°, 15°, 30°, and 45° of flexion, and the force required to displace the patella 1 cm laterally at 10 mm/s was measured. Group comparisons were made with repeated measures analysis of variance. Results: In the setting of an MPFL reconstruction, as the trochlear groove was incrementally flattened, the force required to laterally displace the patella progressively decreased. A 10° increase in the sulcus angle significantly reduced the force at 15° ( P = .01) and 30° ( P = .03) of knee flexion. The force required to laterally displace the patella was also significantly lower at all knee flexion angles after the addition of the 20°, 30°, and 40° wedges ( P≤ .05). Specifically, a 20° increase in the sulcus angle reduced the force by 29% to 36%; a 30° increase, by 35% to 43%; and a 40° increase, by 40% to 47%. Conclusion: Despite an MPFL reconstruction, the force required to laterally displace the patella decreased as the sulcus angle was increased in our cadaveric model. Clinical Relevance: An isolated MPFL reconstruction may not be sufficient to restore patellar stability in the setting of a shallow or flat trochlea. Patients with an abnormal sulcus angle may have recurrent instability postoperatively if treated with an isolated MPFL reconstruction.

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Comparison of Patellofemoral Kinematics and Stability After Medial Patellofemoral Ligament and Medial Quadriceps Tendon–Femoral Ligament Reconstruction

The American Journal of Sports Medicine ◽

10.1177/0363546520930703 ◽

2020 ◽

Vol 48 (9) ◽

pp. 2252-2259

Author(s):

Robert Spang ◽

Jonathan Egan ◽

Philip Hanna ◽

Aron Lechtig ◽

Daniel Haber ◽

...

Keyword(s):

Soft Tissue ◽

Medial Patellofemoral Ligament ◽

Quadriceps Tendon ◽

Mpfl Reconstruction ◽

Fixation Method ◽

Full Extension ◽

Lateral Translation ◽

Patellar Position ◽

Significant Difference ◽

Contact Pressures

Background: There is a lack of evidence regarding the optimum extensor-sided fixation method for medial patellofemoral ligament (MPFL) reconstruction. There is increased interest in avoiding patellar drilling via soft tissue–only fixation to the distal quadriceps, thus reconstructing the medial quadriceps tendon–femoral ligament (MQTFL). The biomechanical implications of differing extensor-sided fixation constructs remain unknown. Hypothesis: The null hypothesis was there would be no differences between traditional MPFL reconstruction and MQTFL reconstruction with respect to resistance to lateral translation, patellar position, or patellofemoral contact pressures. Study Design: Controlled laboratory study. Methods: Nine adult knee specimens were mounted on a jig that applied static, physiologic loads to the quadriceps tendons. Patellar position and orientation, knee flexion angle, and patellofemoral pressure were recorded at 8 different flexion angles between 0° and 110°. Additionally, a lateral patellar excursion test was conducted wherein a load was applied directly to the patella in the lateral direction with the knee at 30° of flexion and subjected to 2-N quadriceps loads. Testing was conducted under 4 conditions: intact, transected MPFL, MQTFL reconstruction, and MPFL reconstruction. For MQTFL reconstruction, the surgical technique established by Fulkerson was employed. For MPFL reconstruction, a traditional technique was utilized. Results: The patellar excursion test showed no significant difference between the MQTFL and intact states with respect to lateral translation. MPFL reconstruction led to significantly less lateral translation ( P < .05) than all other states. There were no significant differences between MPFL and MQTFL reconstructions with respect to peak patellofemoral contact pressure. MPFL and MQTFL reconstructions both resulted in increased internal rotation of the patella with the knee in full extension. Conclusion: Soft tissue-only extensor-sided fixation to the distal quadriceps (MQTFL) during patella stabilization appears to re-create native stability in this time 0 cadaver model. Fixation to the patella (MPFL) was associated with increased resistance to lateral translation. Clinical Relevance: Evolving anatomic knowledge and concern for patellar fracture has led to increased interest in MQTFL reconstruction. Both MQTFL and MPFL reconstructions restored patellofemoral stability to lateral translation without increasing contact pressures under appropriate graft tensioning, with MQTFL more closely restoring native resistance to lateral translation at the time of surgery.

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Comparative Study of Biomechanical Properties between Needled Suture and Needleless Suture in Multi-Strand Tendon Graft Model

Journal of the Medical Association of Thailand ◽

10.35755/jmedassocthai.2021.09.12507 ◽

2021 ◽

Vol 104 (9) ◽

pp. 1447-1451

Keyword(s):

Testing Machine ◽

Biomechanical Properties ◽

Tendon Graft ◽

Suture Technique ◽

Biomechanical Study ◽

Modes Of Failure ◽

Tendon Elongation ◽

Significant Difference ◽

Load To Failure ◽

Distraction Force

Objective: To compare the biomechanical properties of the Chinese finger (CF) suture, a needleless suture technique, with the baseball stitch (BS) suture, a needled suture technique, in a multi-strand model by using a 4-strand tendon model. Additionally, the BS was compared with the serial rolling hitch (RH), a locking needleless suture technique. Materials and Methods: 4-strand grafts, made from two 20-cm fresh porcine toe extensors, were used in all three groups. After the grafts were sutured, pretension was applied with a load of 100-N distraction force for five minutes. After the tendon elongation was measured before and after the pretension, the distraction force was continued until the constructed graft failed. Stress-strain relationship graphs were recorded by universal testing machine (UTM), distributing to the calculation of percentage on tendon elongation, stiffness, and load-to-failure. Results: The BS had significantly higher load of failure than the CF (p=0.001) but no significant difference when compared with the RH. Comparing between BS, CF, and RH, there were no significant difference in stiffness and percentage of tendon elongation. In modes of failure, there was evidence of knot slipping in CF in six of six cases and graft strangulation in RH in four of six cases. Conclusion: Multi-strand model BS, a needled suture, had a higher load to failure than CF, a needleless suture. Moreover, needleless sutures had serious modes of failure, which were knot slipping and strangulation of graft by the suture material. Therefore, needleless suture technique for multi-strand tendon graft preparation was not recommended. Keywords: Tendon preparation; Multi-Strand; Needled suture; Needleless suture; Chinese finger; Baseball stitch; Rolling Hitch; Biomechanical study; Graft elongation; Load to failure

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Biomechanical evaluation of cervical lateral mass fixation: a comparison of the Roy-Camille and Magerl screw techniques

Journal of Neurosurgery Spine ◽

10.3171/spi.2004.100.3.0268 ◽

2004 ◽

Vol 100 (3) ◽

pp. 268-276 ◽

Cited By ~ 7

Author(s):

Cédric Barrey ◽

Patrick Mertens ◽

Claude Rumelhart ◽

François Cotton ◽

Jérôme Jund ◽

...

Keyword(s):

Testing Machine ◽

Biomechanical Study ◽

Lateral Mass ◽

Mineral Density ◽

Vertebral Level ◽

Content Type ◽

Pullout Force ◽

Significant Difference ◽

The Difference ◽

Fine Print

Object. The purpose of this study was to assess human cervical spine pullout force after lateral mass fixation involving two different techniques: the Roy-Camille and the Magerl techniques. Although such comparisons have been conducted previously, because of the heterogeneity of results and the importance of this procedure in clinical practice, it is essential to have data derived from a prospective and randomized biomechanical study involving a sufficient sample of human cervical spines. The authors also evaluated the influence of the sex, the vertebral level, the bone mineral density (BMD), the length of bone purchase, and the thickness of the anterior cortical purchase. Methods. Twenty-one adult cervical spines were harvested from fresh human cadavers. Computerized tomography was performed before and after placing 3.5-mm titanium lateral mass screws from C-3 to C-6. Pullout forces were evaluated using a material testing machine. The load was applied until the pullout of the screw was observed. A total of 152 pullout tests were available, 76 for each type of screw fixation. The statistical analysis was mainly performed using the Kaplan—Meier survival method. The mean pullout force was 266 ± 124 N for the Roy-Camille technique and 231 ± 94 N for the Magerl technique (p < 0.025). For the C3–4 specimen group, Roy-Camille screws were demonstrated to exert a significantly higher resistance to pullout forces (299 ± 114 N) compared with Magerl screws (242 ± 97 N), whereas no difference was found between the two techniques for the C5–6 specimen group (Roy-Camille 236 ± 122 N and Magerl 220 ± 86 N). Independent of the procedure, pullout strengths were greater at the C3–4 level (271 ± 114 N) than the C5–6 level (228 ± 105 N) (p < 0.05). No significant correlation between the cancellous BMD, the thickness of the anterior cortical purchase, the length of bone purchase, and maximal pullout forces was found for either technique. Conclusions. The difference between pullout forces associated with the Roy-Camille and the Magerl techniques was not as significant as has been previously suggested in the literature. It was interesting to note the influence of the vertebral level: Roy-Camille screws demonstrated greater pullout strength (23%) at the C3–4 vertebral level than Magerl screws but no significant difference between the techniques was observed at C5–6.

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Arthroscopic Repair of Articular Surface Partial-Thickness Rotator Cuff Tears: Transtendon Technique versus Repair after Completion of the Tear—A Meta-Analysis

Advances in Orthopedics ◽

10.1155/2016/7468054 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 9

Author(s):

Yohei Ono ◽

Jarret M. Woodmass ◽

Aaron J. Bois ◽

Richard S. Boorman ◽

Gail M. Thornton ◽

...

Keyword(s):

Rotator Cuff ◽

Clinical Outcomes ◽

Articular Surface ◽

Constant Score ◽

Surgical Techniques ◽

Arthroscopic Repair ◽

Rotator Cuff Tears ◽

Long Term Outcome ◽

Partial Thickness ◽

Significant Difference

Articular surface partial-thickness rotator cuff tears (PTRCTs) are commonly repaired using two different surgical techniques: transtendon repair or repair after completion of the tear. Although a number of studies have demonstrated excellent clinical outcomes, it is unclear which technique may provide superior clinical outcomes and tendon healing. The purpose was to evaluate and compare the clinical outcomes following arthroscopic repair of articular surface PTRCT using a transtendon technique or completion of the tear. A systematic review of the literature was performed following PRISMA guidelines and checklist. The objective outcome measures evaluated in this study were the Constant Score, American Shoulder and Elbow Surgeons score, Visual Analogue Scale, physical examination, and complications. Three studies met our criteria. All were prospective randomized comparative studies with level II evidence and published from 2012 to 2013. A total of 182 shoulders (mean age 53.7 years; mean follow-up 40.5 months) were analyzed as part of this study. Both procedures provided excellent clinical outcomes with no significant difference in Constant Score and other measures between the procedures. Both procedures demonstrated improved clinical outcomes. However, there were no significant differences between each technique. Further studies are required to determine the long-term outcome of each technique.

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Percentage of Articular Surface Debridement is Equivalent in Arthroscopic and Open Ankle Fusions

Foot & Ankle Orthopaedics ◽

10.1177/2473011417s000094 ◽

2017 ◽

Vol 2 (3) ◽

pp. 2473011417S0000

Author(s):

Michael Anderson ◽

Ashlee MacDonald ◽

Sandeep Soin ◽

Adolph Flemister ◽

John Ketz

Keyword(s):

Soft Tissue ◽

Ankle Joint ◽

Articular Surface ◽

Wound Complications ◽

Arthroscopic Debridement ◽

Talar Dome ◽

Ankle Arthritis ◽

Tibial Plafond ◽

Significant Difference ◽

Open Debridement

Category: Ankle Arthritis, Arthroscopy Introduction/Purpose: Tibiotalar arthrodesis is a reliable option in the treatment of end-stage ankle arthritis and both open and arthroscopically assisted techniques are well described. When compared head to head, multiple studies have demonstrated advantages of arthroscopic arthrodesis over open fusions including decreased morbidity, and shorter hospital stays while achieving equivalent or increased rates of fusion. It is unclear why arthroscopic fusion may be favorable to open surgery, however, it is hypothesized that patient selection and soft tissue trauma may play a role. No study, however, has evaluated the extent of articular debridement afforded by each technique. The purpose of this study was to evaluate the amount of articular cartilage denuded via open arthrodesis and via arthroscopic arthrodesis with time of procedure evaluated as a secondary measure. Methods: Six matched sets of fresh frozen cadaver lower extremities were acquired for study. One limb from each set was randomly assigned to open articular debridement while the other limb was assigned to arthroscopic debridement. The duration of each procedure was timed. The tibiotalar joints were disarticulated following debridement and the talus was dissected free of all soft tissue attachments. Photographs of the weight bearing portion of the articular surfaces were then taken and residual cartilage was mapped using ImageJ software. The percentage of the joint debrided was determined by the area of denuded bone divided by the total area of the articular surface to allow for comparison across specimens. The mapping process was blinded to the type of debridement undertaken. Repeated measurements were taken to determine intra- and inter-reliability of the measurements. Student t-tests were used to compare the percentage of joint debrided and differences in time of the procedure. Results: The average percentage of cartilage debrided in the arthroscopic procedure was 88.99+11.19% for the tibial plafond and 88.84.08+5.45% for the talar dome. For the open procedure, 82.93+6.91% of the tibial plafond was debrided and 84.08+5.45% of the talar dome was debrided. There were no significant differences of the tibia or talus between the open and arthroscopic procedures (p>0.05). Inter- and intra-reliability were calculated for all measurements with r>.8. There was a significant difference in the time of the procedure with the arthroscopic debridement taking 50.17+5.57 minutes to complete while the open debridement took 30.67+5.16 minutes to complete (p<0.01). Conclusion: There were no differences in the percentage of articular surface debrided when comparing arthroscopic versus open arthrodesis of the ankle joint in cadaver specimens. The arthroscopic debridement took significantly longer, however this difference may be offset by a decrease in time required for wound closure. Furthermore, an increased time of debridement may be warranted if it results in decreased wound complications and pain. The results of this study support previous clinical findings that arthroscopic debridement can yield fusion rates comparable to, or better, than open debridement of the ankle joint.

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Operative outcome of high energy pilon fractures: a retrospective comparison between internal fixation and Ilizarov external fixation

International Journal of Research in Orthopaedics ◽

10.18203/issn.2455-4510.intjresorthop20170078 ◽

2017 ◽

Vol 3 (2) ◽

pp. 177

Author(s):

Satya Ranjan Patra ◽

Dasarath Kisan ◽

Naresh Kumar Panigrahi ◽

Dibya Singha Das ◽

Medini Manoj ◽

...

Keyword(s):

Soft Tissue ◽

Internal Fixation ◽

Treatment Plan ◽

Surgical Techniques ◽

High Energy ◽

Minimal Invasive ◽

Fixation Group ◽

Significant Difference ◽

Tract Infections ◽

Pilon Fractures

Background: Pilon fractures are serious injuries with many devastating soft-tissue complications associated with them. Deciding a definite treatment plan has always proved a challenge. Comparative studies between the various surgical techniques used for pilon fractures are uncommon and consensus is yet to be reached regarding the best surgical option. Purpose of this study is to retrospectively compare the operative results (complications, functional and radiographic outcomes) of pilon fractures treated either with internal fixation or Ilizarov ring fixators.Methods: Forty-six patients with pilon fractures were retrospectively studied; twenty-one of them had minimal invasive fixation by ankle spanning Ilizarov fixators and 25 patients had internal fixations by either minimal invasive plate osteosynthesis (MIPO) or by open reduction. The patients were followed-up for a mean of 34 months (range, 24-51 months).Results: The internal fixation group had a higher incidence of soft-tissue complications and deep infections. In comparison the Ilizarov group had only superficial pin-tract infections but no other soft-tissue complications. Although the Ilizarov group had a higher incidence of malreduction and malunion in their series compared to the internal fixation group, there was no significant difference in the AOFAS ankle function score (p-value 0.2922) between the two groups after a follow-up of 2-4 years.Conclusions: The moderately long term functional outcome appears to be similar in both internal fixation and Ilizarov groups. But the Ilizarov technique is less likely to cause any serious peri-operative soft-tissue complications or deep infection. Familiarity of the surgeon with a particular technique should also be considered during surgical decision making.

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Development of a cadaveric Hallux Rigidus model. Biomechanical testing

Foot & Ankle Orthopaedics ◽

10.1177/2473011417s000426 ◽

2017 ◽

Vol 2 (3) ◽

pp. 2473011417S0004

Author(s):

Diego Zanolli de Solminihac ◽

Emilio Wagner ◽

Pablo Wagner ◽

Cristian Ortiz ◽

Andres Keller Díaz ◽

...

Keyword(s):

Range Of Motion ◽

Tensile Testing ◽

Soft Tissues ◽

Testing Machine ◽

Distal Tibia ◽

Joint Stiffness ◽

Hallux Rigidus ◽

Tensile Testing Machine ◽

Significant Difference ◽

Cadaveric Model

Category: Bunion Introduction/Purpose: Hallux Rigidus (HR) is characterized initially by a decrease in Hallux metatarsophalangeal joint (MTPJ) dorsiflexion, decreasing the total range of motion. To be able to study different surgical treatment options, a cadaveric model has to be developed that recreates the limited range of motion. Our objective was to develop an Hallux Rigidus cadaveric model by shortening the plantar fascia (PF). Hallux MTPJ range of motion and joint stiffness were evaluated. Methods: 8 cadaveric foot- ankle – distal tibia specimens were prepared, identifying all extensor and flexor tendons proximally. The skin and subcutaneous tissue was kept intact. Each specimen was mounted on a special frame and luminous markers were attached to the skin (Oxford Foot Model). A dead weight equal to 50% of the stance phase force was applied to each tendon, except for the Achilles tendon and the posterior tibialis. 10 Hallux MTPJ dorsiflexion-plantarflexion cycles were performed by pulling the Extensor Hallucis longus tendon using an tensile testing machine (Kinetecnics). A Hallux Rigidus model was then developed by shortening the PF by 6 mm using a triple fiberwire suture technique. The same 10 cycles were repeated with a shortened PF. Each specimen served as its own control. Hallux metatarsophalangeal stiffness and kinematics were tested using a tensile testing machine and high definition cameras. Results: The group with a shortened PF significantly reduced the hallux dorsiflexion (18.6 degrees) compared to the native foot (23.7 degress) (p<0.05). No significant difference in joint stiffness was seen between groups: 3.3 N per degree for the native foot and 4.3 N per degree for the Hallux Rigidus model (P>0.05). Conclusion: To create a HR model is vital to allow further understanding of the pathology. The cadaveric model should not alter the joint stability (intact periarticular soft tissues) but has to limit Hallux range of motion. The model we present successfully recreates HR by limiting MTPJ dorsiflexion. The absence of stiffness change shows that joint congruity and isometry were not modified. There are a few reports that state a PF shortening as the first stage in HR. This would lead to a hinge-like MTPJ dorsiflexion, creating a dorsal metatarsal head impingement that could evolve to a dorsal exostosis.

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Biomechanical Comparison of Surgical Techniques for Resection Arthroplasty of the Sternoclavicular Joint

The American Journal of Sports Medicine ◽

10.1177/0363546516639302 ◽

2016 ◽

Vol 44 (7) ◽

pp. 1832-1836 ◽

Cited By ~ 11

Author(s):

J. Christoph Katthagen ◽

Daniel Cole Marchetti ◽

Kimi D. Dahl ◽

Travis Lee Turnbull ◽

Peter J. Millett

Keyword(s):

Testing Machine ◽

Surgical Techniques ◽

Resection Arthroplasty ◽

Matched Pair ◽

Posttraumatic Arthritis ◽

Force Transmission ◽

Articular Disc ◽

Tensile Testing Machine ◽

Medial Clavicle ◽

Parallel Technique

Background: The optimal location and extent of medial clavicle resection for sternoclavicular (SC) joint resection arthroplasty are unknown. Hypothesis: Resection of the intra-articular disc alone cannot reliably decompress the SC joint, and a parallel resection technique will decompress the SC joint significantly more compared with the same amount with an oblique resection technique. Study Design: Controlled laboratory study. Methods: Force transmission through the SC joint was measured in 7 matched-pair human cadaveric SC joints in a dynamic tensile testing machine. The specimens were randomized to either a parallel or an oblique resection technique. An 80-N axial load was applied on the lateral clavicle toward the SC joint in each of the following 4 conditions: (1) intact joint, (2) after resecting the intra-articular disc, (3) after resecting 5 mm of the medial clavicle, and (4) after 10-mm resection. Results: Complete discectomy of all SC joints resulted in a significant reduction of force transmitted through the SC joint ( P = .002). However, the varying anatomy of the disc was accompanied by a varying amount of joint decompression (95% CI, 29.8%-65.4%). Resecting 5 mm of the SC joint with the parallel technique decompressed the SC joint by a mean (±SD) of 76.7 ± 22.1 N compared with 37.8 ± 24.8 N with the oblique technique ( P = .02). Decompression did not significantly differ between the groups after 10-mm resection ( P = .18) using the parallel technique (89.4 ± 24.1 N) compared with the oblique technique (68.2 ± 31.6 N). Furthermore, 5-mm resection of the medial end of the clavicle with the parallel technique decompressed the SC joint by an amount similar to 10-mm resection with the oblique technique. Conclusion: Resection of the disc alone did not reliably decompress each SC joint. Resection of 5 mm of the medial end of the clavicle with the parallel resection technique reliably decompressed the SC joint better than with the oblique resection technique. Clinical Relevance: This study provides baseline data on SC joint resection techniques and their mechanical effects. This knowledge can be implemented in clinical practice to treat patients with symptomatic posttraumatic arthritis of the SC joint.

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