Introduction: Functional results of hemiarthroplasties in proximal humeral fractures are unpredictable. The correct consolidation of the tuberosities back to the prosthesis seem to be of capital importance in the functional outcome. The objective of the study is to analyze the changes of the tension registered in the sutures passed through the tuberosities when changing the height and version of the prosthesis in a static model and in a dynamic model. Material and Method: Prosthesis positioning: in both static and dynamic model, the prosthesis was placed in anatomical position, anatomical increasing 20° retroversion, increasing height in 1cm and anatomical version, decreasing height in 1 cm and anatomical version, increasing height in 1cm and increasing 20° retroversion, decreasing height in 1 cm and increasing 20° retroversion,. Static study: a 4-part fracture was reproduced in four fresh-frozen shoulder specimens. Sutures were placed between lesser tuberosity and diafisis (sensor 1) between both tuberosities (sensor 2) and between greater tuberosity and diafisis (sensor 3). Traction was performed through supraspinatus, infraspinatus and subescapularis attachments until the breakage of the suture or 1 cm gap between bony fragments. Tensions registered in a computer model. Dynamic study: a 4-part fracture was reproduced in a humeral saw bone. Sutures placed in the same position that in the static model. Saw bone fixed at a robotic arm reproducing cycles of 90° anterior elevation, 30° lateral rotation, 30° internal rotation and retropulsion to starting point. Registering of the tensions. Quantitative values studied through t-student and non parametric values studied through U-Mann-Whitney and Kruskal-Wallis test. Results: In the Static study, the suture placed between the tuberosities is the one that significantly receives more tension. The breakage of the suture happens more frequently when the prosthesis is placed in a lower position and in a lower more retroverted position. In the dynamic study, the suture placed between the greater tuberosity and the diafisis is the one significantly receives more tension. The breakage of the suture happens more frequently when the prosthesis is placed in a lower position and in a lower more retroverted position. Conclusions: When planning sutures between tuberosities in proximal humeral fractures treated with hemiarthroplasty postoperative rehabilitation program has to be considered because different sutures are at risk depending on static or dynamic model. The worst positions of the hemiarthroplasty as far as over tensioning sutures is concerned are the low position and the low more retroverted position

Introduction: Closure with interrupted mattress sutures is useful where careful skin apposition is required following hindfoot surgery. However, suture removal around the hindfoot can be awkward and painful. Modification with an additional loop creates a “traction loop suture”. We hypothesise this technique makes removal easier and reduced tension placed on sutures during their removal reduces pain.

Materials: 17 patients undergoing elective hindfoot surgery were included. Nylon suture was used for all wound closures. Suturing and removal techniques were standardised. Ethical approval and patient consent was obtained.

Methods: Half of each wound length was sutured normally and the other with traction loop sutures (both interrupted mattress type). Follow-up was at 2 and 6 weeks. Comparison of time taken for suture removal and associated wound complications were noted for both. Pain scores during suture removal were recorded using a screen to “blind” the patient and a visual analogue pain score (VAPS) was obtained. Statistical analysis calculated p-values at the 5% significance level and 95% confidence intervals (CI).

Results: Traction loop sutures were 20% faster to remove than normal interrupted sutures (mean difference 19.3 seconds, CI 5.39 to 33.1 seconds, p-value 0.004). Traction loop sutures were also 20% less painful during removal (mean difference 1.05 on VAPS, CI 0.021 to 2.085, p-value 0.027. At 2 weeks, 1 normally sutured wound suffered complications. At 6 weeks, no complications were noted in either group.

Discussion: Traction loop sutures provide a statistically significant method of reducing pain and time during suture removal. The study method could be applied to comparisons of other skin closures where removal is required. The technique is novel and requires minimal change in suturing.

Conclusion: Pain levels and time taken for removal of interrupted mattress sutures are significantly reduced using the traction loop suture technique in hindfoot surgery. The study is continuing.

Recently, a new suture was designed to minimize laxity in order to preserve consistent tissue approximation while improving footprint compression after tendon repair. The aims of this study were: (1) to compare the biomechanical competence of two different high strength sutures in terms of slippage and failure load, (2) to investigate the influence of both knots number and different media (air, saline and fat) on the holding capacity of the knots.

Alternating surgical knots of two different high-strength sutures (group1: FibreWire; group2: DynaCord; n = 105) were tied on two roller bearings with 50N tightening force. Biomechanical testing was performed in each medium applying ramped monotonic tension to failure defined in terms of either knot slippage or suture rupture. For each group and medium, seven specimens with either 3, 4, 5, 6, or 7 knots each were tested, evaluating their knot slippage and ultimate load to failure. The minimum number of knots preventing slippage failure and thus resulting in suture rupture was determined in each group and medium, and taken as a criterium for better performance when comparing the groups.

In each group and medium failure occurred via suture rupture in all specimens for the following minimum knot numbers: group1: air – 7, saline – 7, fat – 7; group2: air – 6; saline – 4; fat – 5. The direct comparison between the groups when using 7 knots demonstrated significantly larger slippage in group1 (6.5 ± 2.2 mm) versus group2 (3.5 ± 0.4 mm) in saline (p < 0.01) but not in the other media (p ≥0.52). Ultimate load was comparable between the two groups for all three media (p ≥ 0.06).

The lower number of required knots providing sufficient repair stability, smaller slippage levels and identical suture strength, combined with the known laxity alleviation effect demonstrate advantages of DynaCord versus FibreWire.

Aims

Although absorbable sutures for the repair of acute Achilles tendon rupture (ATR) have been attracting attention, the rationale for their use remains insufficient. This study prospectively compared the outcomes of absorbable and nonabsorbable sutures for the repair of acute ATR.

Introduction

A recent meta-analysis published in the British Medical Journal suggested an increased risk of infection, but none of the studies were large enough to reach statistical significance. A prospective, randomised trial was designed at our institution to investigate the wound healing and complications related to surgery following fracture neck of femur in the elderly.

Currently there is an elevated public awareness of the consequences of nosocomial infection, of which, 14.5% is due to surgical site infection (SSI). Hip fracture patients are at increased risk of SSI due to their age related poor medical health, immune response impairments and decreased capacity of wound healing. Superficial SSI following hip fracture surgery can affect up to 16.9% with deep infection affecting 3.7%. Deep infection represents a major complication, from which hip fracture patients are 4.5 times less likely to survive to discharge and carries a 50% mortality at 1 year, compared to 33% without infection. Treatment requires a prolonged hospital stay, additional diagnostic testing, antibiotic therapy and surgery, resulting in the total cost of treating deep infection to be more than double that of non-infected hip fracture surgery.

Wound closure aims to accurately appose the skin edges thereby promoting rapid healing and restoration of the protective dermal barrier. Failure to provide accurate skin apposition can result in delayed wound healing which has been shown to have a 3 fold risk of developing late infection. Importantly, delayed wound healing is reflected by prolonged wound ooze. We hypothesized that skin closure via sutures is better at achieving skin edge apposition than wounds closed with staples, providing more rapid wound healing. We compared staples and sutures for wound closure in hip fracture patients by using ooze duration as an outcome measure for wound healing.

Duration of wound ooze was recorded in 170 patients. 65 wounds, closed with sutures, had an average duration of ooze of 1.82 days. 105 wounds, closed with staples, had an average duration of ooze of 4.97 days. This study suggests that sutures are superior to staples with regard to early wound healing in hip fracture patients.

This is a retrospective comparative review of the clinical results of arthroscopic meniscal repairs between the use of meniscal arrows and sutures. The study group consists of 37 repairs in 35 patients carried out by 2 special knee surgeons over a five-year period.

The arrow group consisted of 23 repairs in 21 patients. There were 14 males and 7 females. The medial meniscus was repaired in 13 and the lateral in 10 cases. Associated anterior cruciate ligament injured was present in 11 patients, of whom 9 underwent concomitant reconstruction along with the meniscal repair.

The suture group comprised 14 cases. Ten were male and 4 female. There were 8 medial meniscal repairs and 6 lateral.

The anterior cruciate was also torn in 8 cases, of whom 6 had it reconstructed. The repairs were carried out use #0-PDS by an out-to-in technique.

The 2 groups were grossly age and sex matched. Tears were located in zone 0/1, mainly in the posterior third segment of the meniscus. The rehabilitation protocol was similar in both groups. Minimum follow up was 9 months. Patients were evaluated by clinical review; questionnaire based on the Lysholm score and case record analysis. The overall clinical success rate for the arrows group was 13/23 (56.5%) compared to 11/14 (78.6%) for the suture group. Complications noted were broken arrows – 4 cases, cutaneous nerve entrapment by suture – 1, and delayed portal healing due to suture irritation – 1.

In conclusion, arthroscopic suture repair provided better clinical healing rates than meniscal arrows. Arrow breakage is a significant factor contributing to non-healing of initial tear repairs.

We treated 133 traumatic posterior dislocations surgically between July 1994 and March 2001. In 16 patients, labral tears had occurred.

Operating on posterior hip dislocations, initially we fixated the posterior wall with screws and/or buttress plate, depending on the size of the fragment, and did suture the torn labrum, relying rather on the buttress plate or intact posterior wall for stability.

We began repairing the torn labrum when we realised that any small fragments still attached to the labrum simply pull out from under the buttress plate, allowing the hip to redislocate. Once the wall has been reconstructed, interrupted sutures are passed through the labrum, with the hip internally rotated to prevent shortening of the capsule when sutures are tied. A one-third tubular plate is placed over the sutures lying on the posterior wall and fixed with screws. The sutures are then tied individually over the plate. Postoperatively the patient is kept in bed for six weeks, with the hip abducted and knee extended.

Seven patients in whom the labrum was not repaired experienced redislocation. We performed second operations on two of them, repositioning the plates and reconstructing the posterior wall, but redislocation again occurred. The redislocated femoral heads were damaged because they rubbed against the plate and screws. In the other nine patients, we sutured the labrum, and in a 3 month to 2.5 year follow-up, no redislocation has occurred. .

Labral repair restores stability, and tying interrupted sutures over a buttress plate is an easy and effective method of repair.

Background

Patellar ligament rupture is an uncommon but devastating complication of total knee arthroplasty. Many predisposing factors may lead to rupture of the ligament during or shortly after surgery. The most common predisposing factor is extensive release of the ligament to improve exposure in difficult cases or revisions.

We compared the initial strength of two techniques for repair of rotator cuff tears. Eight paired cadaveric shoulders with a standardized supraspinatus defect were studied. A transosseous suture and anchor repair was conducted on each side. Specimens were tested under cyclic loading, while fixation was monitored with an optical tracking technique. Mode of failure, number of cycles and load to failure were measured for 50% (5 mm) and 100% (10 mm) loss of repair. Anchors provide improved repair strength at 50% repair loss, in comparison to sutures (p< 0.05). Strength was unaffected by bone mineral density, age and gender.

The purpose of this study was to compare the initial strength of two rotator cuff repair techniques.

Repair strength with anchors was superior to sutures. Strength was unaffected by bone quality.

Anchors, enabling a quicker, less invasive arthroscopic repair, offer improved fixation over sutures, which are more time consuming and invasive.

Eight paired shoulders with a standardized supra-spinatus defect were randomized to anchor or suture repair, and subjected to cyclic loading. Repair migration was measured using a digital camera. Failure mode, cycles and load were measured for 50% and 100% loss of repair. Results were correlated with bone mineral density, age and gender.

The anchors failed at the anchor-tendon interface, whereas the sutures failed through the sutures. Mean values for 50% loss of repair were 205.6 ± 87.5 cycles and 43.8 ± 14.8 N for the sutures, and 1192.5 ± 251.7 cycles and 156.3 ± 19.9 N for the anchors (p< 0.05). The corresponding values for 100% loss of repair were 2457.5 ± 378.6 cycles and 293.8 ± 27.4 N for the sutures, and 2291.9 ± 332.9 cycles and 262.5 ± 28.0 N for the anchors (p> 0.05). These results did not correlate with bone quality.

This study has demonstrated that anchors provide improved repair strength, in comparison to sutures. This may be due to the relative less deformability of the anchors. Repair strength did not correlate with bone quality. This may be attributed to each repair failing primarily through the repair construct or at the anchor-tendon interface, and not through bone.

Introduction and Aims: Suture anchors allow consistent reattachment of tendons and ligaments to bone. Many options are available. The purpose of this study was to compare the initial strength of two rotator cuff repair techniques. The hypothesis was that rotator cuff repair strength with anchors would be inferior to transosseous sutures.

Method: Eight paired shoulders with a standardised supraspinatus defect were randomised to bioabsorbable nonsuture-based anchor or transosseous suture repair. Each specimen was then subjected to a stepwise cyclic loading protocol, utilising a custom-designed loading apparatus. Repair site migration was measured using an optical measurement system, consisting of a digital camera and custom software. Mode of failure, number of cycles and load to failure were measured for 50% (5 mm) and 100% (10 mm) loss of repair. These results were correlated with bone mineral density, age and gender. Statistical analysis utilised paired t-tests and Pearson correlations.

Results: The anchors failed at the anchor-tendon interface, whereas the sutures failed through the sutures. Mean values for 50 percent loss of repair were 206 ± 88 cycles and 44 ± 15 N for the sutures, and 1193 ± 252 cycles and 156 ± 20 N for the anchors (p< 0.05). The corresponding values for 100 percent loss of repair were 2458 ± 379 cycles and 294 ± 27 N for the sutures, and 2292 ± 333 cycles and 263 ± 28 N for the anchors (p> 0.05). These results may be due to the relative less deformability of the anchors. This may be relevant clinically, as in the early post-operative period, while tendon healing to bone is occurring, anchors may offer improved strength, allowing improved initial healing. Strength was unaffected by bone quality. This may be attributed to each repair failing primarily through the repair construct or at the anchor-tendon interface, and not through bone. Strengths of this study include the use of paired specimens, the stepwise cyclic loading protocol, as well as increased accuracy of our measurement system. Limitations include the use of an in vitro model, as well as a simulated, standardised rotator cuff tear.

Conclusion: Repair strength with anchors was superior to sutures. Strength was unaffected by bone quality. Anchors facilitate an arthroscopic procedure, decrease operative time, and may allow a faster post-operative recovery. This study has described a new high-resolution method of measuring tendon repair failure and may be useful in future studies.

Purpose: New high-strength sutures demonstrate high failure loads, but may be more likely to slip compared with polyester sutures. The purpose of this study was to determine the knot security and ultimate failure load of 8 common sutures tied with 6 arthroscopic knots. The hypothesis was that knots tied using high-strength sutures would not slip and demonstrate greater tensile strengths than polyester suture.

Method: Eight different sutures (Ethibond, FiberWire, ForceFiber, Hi-Fi, MagnumWire, Maxbraid, Ortho-cord and Ultrabraid) were tied with 6 arthroscopic knots (Duncan, Revo, San Diego, SMC, Tennessee and Weston.) Knots were backed up with 4 reversed half-hitches on alternating posts. Each suture-knot combination was tied 10 times for a total of 480 knots tested. Cyclic testing was performed followed by loading to failure. Mode of failure, ultimate failure load and force during slippage was recorded.

Results: FiberWire demonstrated the highest failure load (259.70N+/−85.81) and Ethibond the lowest (143.92N+/−16.56) (p< 0.05). Knots tied with Ethibond slipped 22.4% of the time compared with 31.7%–40.0% for high-strength sutures. Frequent slippage occurred with Duncan loops (97.5%) and Weston knots (86.3%) while the SMC (1.3%) and Revo knots (3.6%) rarely slipped (p< 0.05). Mean failure loads were highest for the Revo (280.99N +/− 57.01) and SMC knots (274.89N +/−57.90) compared with all others (p< 0.05).

Conclusion: Our results demonstrate that knots tied with Ethibond were least likely to slip and yielded a more consistent (narrow standard deviation) but overall lower ultimate tensile strength than all of the high strength sutures. Early slippage of some knots tied with high-strength suture was responsible for greater variability with some failing at sub-maximal loads. The Duncan loop and Weston knots were the most likely to slip.

Introduction and purpose: The treatment of proximal humerus fractures is still controversial in terms of the surgical approach to be used and even of whether surgery is indeed necessary or not. The purpose of this study is to assess the functional result and the patients’ perception of their general health condition after treatment of displaced humerus fractures by means of transosseous sutures with or without the support of modified Ender nails.

Materials and methods: The study comprised a series of 40 patients (mean age: 66.21 years); 82% females /18% males. The patients had the following fracture types: 27% had two-part fractures, 60% had three-part fractures and 12% had four-part fractures and fracture-dislocations. The mean follow-up was 55.83 months (12.83-97). The final functional evaluation was carried out using the Constant score and the health perception was measured on the EuroQol-5D scale. All patients were submitted to a final radiological exam (AP and profile radiographs on the scapular plane).

Results: The mean value obtained on the Constant Scale was 74.18 in the involved arm and 84.06 in the contralateral one. As regards pain, the mean obtained was 12.57, while the value for forward arm elevation was 8.24. When comparing two age groups (> 70 vis-á-vis < 70 year olds) a significant difference was obtained with respect to Constant Scale’s global value (p 0.022). Furthermore, a significant difference was detected between the result of the EuroQol-5D scale, the global result of the Constant Scale (p 0.061), abduction (p 0.05), internal rotation (p 0.05) and strength (p 0.007). The rate of postop complications was 6% (2 surgical wound haematomas). The final radiological control revealed losses in reduction and necrosis in 9.37% and 3.03% of patients respectively.

Conclusions: (1) Good global functional results on he Constant Scale. (2) Significant differences in functional results based on patients’ age. (3) Difference in quality of life perceptions on the basis of the amount of mobility and strength obtained postoperatively. (4) Low complications rate.

This in-vitro study evaluated the influence of ligament tensioning and the effectiveness of lateral collateral ligament (LCL) repair using transosseous sutures on the initial kinematics and stability of the elbow.

Six fresh upper-extremities were mounted in a motion simulator with tracking system, which enabled both passive and simulated active elbow flexion. The intact elbow was tested then the LCL was sectioned from its humeral origin and repaired with a transosseous suture technique. Locking sutures were placed in the LCL and passed through a humeral bone tunnel entering at the centre of curvature of the capitellum with exit holes in the lateral epicondyle. An actuator pulled on the sutures to achieve 20, 40 and 60 N of LCL repair tension and the sutures were then secured. The dependent variable of this study was the motion pathways of the ulna relative to the humerus. The data were analyzed using a two-way, repeated-measures ANOVA with relevant post-hoc paired t-tests.

With the arm oriented in the horizontal position under varus gravity loading, the repairs tracked in greater valgus than the intact LCL regardless of the repair tension. The larger the initial repair tension, the more the elbows tracked in valgus. Initial tension of 60 N was statistically different than the intact LCL with the forearm in pronation (p=0.04). Both the 40 and 60 N initial tensions were statistically different than the intact LCL with the forearm in supination (p< 0.01).

Repair of the LCL using transosseous sutures effectively restores the varus stability of the elbow. The initial tension of LCL repairs affects the kinematics of the elbow, with a tendency to over-tighten the ligament and pull the elbow into valgus. These data suggest that acute repair of the LCL should be performed using a transosseous suture technique, and that a tension of 20N or perhaps less is sufficient to restore stability.

Purpose of Study: To compare the mechanical performance of two commonly used arthroscopic slip knots with that of a hand tied control.

Methods: The arthroscopic slip knots assessed were the Duncan Loop (DL) and the Tautline Hitch (TLH), both of which were tied with arthroscopic knot pushers and secured with Three Reversing Hitches on Alternating Posts (RHAPs). These were compared with four hand tied throws of a squre knot. All three knots were tied using three different materials: number two Ethibond, number one PDS and number two Fiberwire. All knots were tied in a close loop configuration between two metal bars mounted on an Instron materials testing device and pulled apart to both clinical and ultimate failure. Clinical failure was defined as the force in Newtons (N) required to increase loop length by three millimetres, which equtes in vivo with a critical loss in apposition of repaired tissues. Ultimate failure was defined as the force in N resulting in complete slippage or breakage of the knot being tested. This study was different than those before it in that a much larger number of each knot/suture permutation was tested (thirty in each case) to give the study sufficient power to detect significant differences between the knots tested.

Results and Conclusion: Based on the findings of this study, it is our recommendation that an arthroscopic TLH slip knot secured with three RHAPs and tied using a number two Fiberwire suture be used to produce shoulder repairs that are equivalent if not superior to those achieved using open hand tied methods.

Introduction: Olecranon fractures comprise 4–7% of all fractures around the elbow in the pediatric age group. 80% of these fractures can be treated expectantly. Fractures with 2 mm of displacement or more require surgical intervention. The surgical procedure commonly used is ORIF with 2 Kirschner wires and tension band wire as advocated by the AO technique. All open interventions require removal of hardware under anesthesia. We present our experience of five cases treated with percutaneously placed K-wires and absorbable sutures.

Patients and Methods: Five patients, 4 boys and one girl, average age 6 8/12 years (range 4½-14¼ years) with displaced fractures of the olecranon were treated with ORIF during the years 2000–2004. In two cases additional injuries were noted [a displaced lateral condyle fracture in one and a dislocated radial head (Monteggia variant) in another patient].

Under general anesthesia, the olecranon is approached through a posterior incision. After reduction, fixation is achieved with two K-wires, which are inserted percutaneously. Additional fixation is obtained with a heavy absorbable suture (Dexon, PDS) which is fashioned in a figure of eight around the protruding pins and through a hole in the proximal ulna. Stability is checked under vision before wound closure. K-wires are trimmed and a plaster cast is fitted with the elbow in flexion. The plaster cast and K-wires are removed 4 weeks post surgery after X-rays confirm that the fracture is healed and range of motion is started.

Results: Five patients have been treated with our technique; all fractures were reduced and stable in flexion and extension under vision at the end of surgery.

K-wires were removed 4 weeks postoperatively and patients were allowed free range of motion. No immediate complications were noted, none became infected and no loss of fixation was observed.

Conclusions: Anatomic reduction and stable fixation can be achieved by the surgical technique presented. The usual complication of hardware irritation and the need for additional surgery to remove K-wires and the metal TBW are avoided by the use of absorbable sutures and protruding K-wires. Functional outcome is excellent on short term follow-up. Larger numbers and prospective follow-up will tell whether this technique can replace the commonly used methods of olecranon fracture fixation in the pediatric age group.

Suture anchors have gained popularity in recent years, particularly owing to their ease of use for attaching soft tissues to bone and improved biomechanical properties. Three methods to reattach avulsed finger flexor tendons to the distal phalanx were biomechanically compared: a 1.8mm metal Mitek barbed suture anchor, twin 1.3mm PLA suture anchors (Microfix), or a pull-out suture over a button. The suture-anchor interface was tested by pulling the suture at 0, 45, 90° to the anchor's axis. The anchors were tested similarly in plastic foam bone substitute. Repairs of transected tendons in cadaveric fingers were loaded cyclically, then to failure.

The results were subject to statistical analysis using Student t test (p< 0.001) and 1-way ANOVA (p<0.0001). The suture failed prematurely if pulled across the axis of the anchor. Conversely, fixation in bone substitute was stronger when pulling at an angle from the axis. Cyclic loads caused significantly more gap formation in-vitro with twin 1.3mm anchors than the other methods; this method was significantly weaker. The 1.8mm anchor gave similar performance to the pull-out suture and button, while the twin 1.3mm anchors were weaker and vulnerable to gap formation even with passive motion alone.

A suture anchor embedded at between 45 and 90o to the direction of pull gave greater strength than if the pull was in-line. The absorbable 1.3 mm Microfix PLA anchors appeared to be a weak construct, even when twin 1.3 mm anchors were compared to a single metallic 1.8 mm Mitek anchor or the pull-out suture over button technique. All three methods are likely to be satisfactory for reattachment of finger flexor tendons if a low load or non-loading rehabilitation of the hand is planned; however the gap formation on cyclic loading with the Microfix is a concern even if patients are restricted to passive motion.

Lacerations of the FDP tendon in zone one may be reattached to bone with a modified Bunnell pullout suture or with suture anchors. Eleven cadaveric fingers were submitted to cyclical testing of five hundred cycles with either a modified Bunnell pullout suture of 3-0 polypropylene or a micro-Mitek suture anchor with 3-0 Ethibond. Gap formation was 6.6mm in the modified Bunnell group and 2.0mm in the micro-Mitek group (p< 0.001). Load to failure was 37.6N in the pullout group and 28.5N in the anchor group (p< 0.005). Gap in the pullout group and low failure load in the anchor group are of concern.

Distal zone one FDP tendon lacerations are usually re-attached to bone by a modified Bunnell pullout suture of 3-0 polypropylene. This treatment may lead to moderate to severe losses of DIP joint motion in up to 50% of patients. Suture anchors have recently been introduced as a fixation alternative. Cyclical testing simulating five days of a passive mobilisation protocol was used to compare the Micro-Mitek anchor to the modified-Bunnell pullout suture in FDP tendon fixation.

Eleven cadaveric fingers FDP tendons were repaired to bone using a modified Bunnell pullout suture of 3-0 polypropylene or a micro-Mitek anchor with 3-0 Ethibond. Testing was done from 2N to 15N at 5N/sec, for a total of five hundred cycles. Gap formation at the tendon bone interface was measured. Load-to-failure was performed on all specimens.

No specimens failed during cyclic testing. Gap formation was 6.6mm (SD 1.2, range 4.9–8.2mm) and 2.0mm (SD = 0.4, range 1.7–2.7mm) for the pullout technique and the micro-Mitek anchor repair respectively (p< 0.001). Load to failure data was 37.6N (SD 4.7, range 31.8–45.1N) for the pullout group and 28.5N (SD 4.0, range 21.8–33.4N) for the micro-Mitek group (p< 0.005).

This data suggests that both fixation techniques may be adequate to sustain five days of simulated passive rehabilitation therapy. Significant gap formation in the modified Bunnell pullout group is of concern although this needs to be correlated in the clinical setting. The lower failure rate of the micro-Mitek group may leave a narrow margin of safety for passive rehabilitation.

Three methods to reattach avulsed finger flexor tendons to the distal phalanx were compared: a 1.8 mm metal barbed suture anchor, twin 1.3 mm PLA (polylactic acid)absorbable anchors, or a pull-out suture over a button. The suture-anchor interface was tested by pulling the suture at 0, 45, and 90 degrees to the anchor’s axis. The anchors were tested similarly in plastic foam bone substitute. Repairs of transected tendons in cadaveric fingers were loaded cyclically, then to failure. The suture failed prematurely if pulled across the axis of the anchor. Conversely, fixation in bone substitute was stronger when pulling at an angle from the axis. Cyclic loads caused significantly more gap formation in-vitro with twin 1.3 mm absorbable anchors than the other methods; this method was significantly weaker. The 1.8 mm anchor gave similar performance to the pull-out suture over button technique, while the twin 1.3 mm absorbable anchors were weaker and vulnerable to gap formation even with passive motion alone.

Meniscal tears are the most common knee injuries, occurring in acute ruptures or in chronic degenerative conditions. Meniscectomy and meniscal repair are two surgical treatment options. Meniscectomy is easier, faster, and the patient can return to their normal activities earlier. However, this procedure has long-term consequences in the development of degenerative changes in the knee, potentially leading to knee replacement. On the other hand, meniscal repair can offer prolonged benefits to the patients, but it is difficult to perform and requires longer rehabilitation. Sutures are used for meniscal repairs, but they have limitations. They induce tissue damage when passing through the meniscus. Furthermore, under dynamic loading of the knee, they can cause tissue shearing and potentially lead to meniscal repair failure. Our team has developed a new technology of resistant adhesive hydrogels to coat the suture used to repair meniscal tissue. The objective of this study is to biomechanically compare two suture types on bovine menisci specimens: 1) pristine sutures and 2) gel adhesive puncture sealing (GAPS) sutures, on a repaired radial tear under cyclic tensile testing. Five bovine knees were dissected to retrieve the menisci. On the 10 menisci, a complete radial tear was performed. They were separated in two groups and repaired using either pristine (2-0 Vicryl) or GAPS (2-0 Vicryl coated with adhesive hydrogels) with a single stitch and five knots. The repaired menisci were clamped on an Instron machine. The specimens were cyclically preconditioned between one and 10 newtons for 10 cycles and then cyclically loaded for 500 cycles between five and 25 newtons at a frequency of 0.16 Hz. The gap formed between the edges of the tear after 500 cycles was then measured using an electronic measurement device. The suture loop before and after testing was also measured to ensure that there was no suture elongation or loosening of the knot. The groups were compared statistically using Mann-Whitney tests for nonparametric data. The level of significance was set to 0.05. The mean gap formation of the pristine sutures was 5.61 mm (SD = 2.097) after 500 cycles of tensile testing and 2.38 mm (SD = 0.176) for the GAPS sutures. Comparing both groups, the gap formed with the coated sutures was significantly smaller (p = 0.009) than with pristine sutures. The length of the loop was equal before and after loading. Further investigation of tissue damage indicated that the gap was formed by suture filament cutting into the meniscal tissue. The long-term objective of this research is to design a meniscal repair toolbox from which the surgeon can adapt his procedure for each meniscal tear. This preliminary experimentation on bovine menisci is promising because the new GAPS sutures seem to keep the edges of the meniscal tear together better than pristine sutures, with hopes of a clinical correlation with enhanced meniscal healing