Corrective osteotomies of femur and tibia: which factors influence bone healing?

In Vivo Investigation of 3D-Printed Calcium Magnesium Phosphate Wedges in Partial Load Defects

Bone substitutes are ideally biocompatible, osteoconductive, degradable and defect-specific and provide mechanical stability. Magnesium phosphate cements (MPCs) offer high initial stability and faster degradation compared to the well-researched calcium phosphate cements (CPCs). Calcium magnesium phosphate cements (CMPCs) should combine the properties of both and have so far shown promising results. The present study aimed to investigate and compare the degradation and osseointegration behavior of 3D powder-printed wedges of CMPC and MPC in vivo. The wedges were post-treated with phosphoric acid (CMPC) and diammonium hydrogen phosphate (MPC) and implanted in a partially loaded defect model in the proximal rabbit tibia. The evaluation included clinical, in vivo µ-CT and X-ray examinations, histology, energy dispersive X-ray analysis (EDX) and scanning electron microscopy (SEM) for up to 30 weeks. SEM analysis revealed a zone of unreacted material in the MPC, indicating the need to optimize the manufacturing and post-treatment process. However, all materials showed excellent biocompatibility and mechanical stability. After 24 weeks, they were almost completely degraded. The slower degradation rate of the CMPC corresponded more favorably to the bone growth rate compared to the MPC. Due to the promising results of the CMPC in this study, it should be further investigated, for example in defect models with higher load.

Anterior cruciate ligament zoobiquity: Can man's best friend tell us we are being too cautious with the implementation of osteotomy to correct posterior tibial slope

Anterior cruciate ligament (ACL) reconstruction (ACLR) is used to treat clinical instability post ACL rupture, however, there is a high rate of incomplete return to sport and rerupture. There is increasing interest in posterior tibial slope as an intrinsic risk factor for ACLR failure and persistent instability. Zoobiquity describes the collaboration between the human and veterinary professions in order to advance the scientific understanding of both fields. Given the cranial cruciate ligament (CCL) in dogs is synonymous with the anterior cruciate ligament in humans, functioning to control internal rotation and anterior translation, but osteotomies, rather than ligament reconstruction, are the mainstay of treatment for CCL rupture, this editorial sort to gain insights into this form of treatment from the veterinary world. Level of Evidence: Level V, evidence.

Incidence of Complications After Tibial Tubercle Osteotomy and Tibial Tubercle Osteotomy With Distalization

BACKGROUND

Tibial tubercle osteotomy (TTO) is a well-established surgical treatment option for patellofemoral instability and pain. TTO with distalization (TTO-D) is indicated for patients with patellofemoral instability, patellar malalignment, and patella alta. The current literature demonstrates several complications that may be associated with TTO, with reportedly higher rates of complications associated with TTO-D.

PURPOSE

To analyze and compare complication rates after TTO without distalization (TTO-ND) and TTO-D and assess risk factors associated with complications.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All skeletally mature patients who underwent TTO with or without distalization by a single surgeon between September 2014 and May 2023 with a minimum of 6 months of clinical follow-up were retrospectively reviewed. Patient factors, surgical indications, perioperative data, and complications were collected via a retrospective review of electronic medical records. Concomitant procedures were categorized as intra-articular, extra-articular, and osteotomies.

RESULTS

A total of 251 TTOs (117 TTO-D, 134 TTO-ND) were included in the study group. Postoperative complications were observed in 15 operations (6%), with arthrofibrosis as the most common complication (10 operations [4%]). TTO-D and TTO-ND had similar rates of complication (5% vs 7%; P = .793). Clinical nonunion was observed in 3 operations (3%) in the TTO-D cohort and 1 operation (1%) in the TTO-ND cohort. In the TTO-D cohort, concomitant intra-articular procedures were significantly associated with an increased likelihood of complications in a univariate model. In the TTO-ND cohort, an increased tourniquet time was significantly associated with an increased likelihood of complications in a univariate model. For all TTOs as well as the TTO-D and TTO-ND cohorts, there were no significant associations between patient or surgical variables in a multivariate model.

CONCLUSION

TTO with and without distalization is a safe procedure with low rates of complication. TTO-D was not associated with a higher rate of complications compared with TTO-ND. There was no association between complications and surgical variables for TTO procedures.

The effect of smoking on union rates following corrective osteotomies around the knee: A systematic review and meta-analysis

BACKGROUND

Distal femur osteotomies (DFO) and high tibial osteotomies (HTO), are well-established treatment options for joint preservation in active patients with uni-compartmental osteoarthritis. Optimal outcomes are contingent on adequate preoperative evaluation of patient-specific factors. This systematic review and meta-analysis aims to explore the difference in union rates between smokers and non-smokers following corrective osteotomies around the knee.

METHODS

A systematic search of the MEDLINE and EMBASE databases was performed in accordance with the PRISMA guidelines to identify studies reporting smoking status in adults who developed delayed and/or non-union following HTO or DFO. Studies were pooled using a random effect model [Review Manager (RevMan) software, V.5.4] and heterogeneity was estimated using I2.

RESULTS

Data for meta-analysis was available for 1,406 osteotomies from 10 studies, performed in patients with mean age ranging from 38-54 years, and 65% were male. The union rate among non-smokers was 97.3% (1100/1131) compared with 89.5% (246/275) among smokers; OR 4.59 [95% CI 1.99 to 10.62], p-value < 0.001. Subgroup analysis revealed that the risk of non-union in smokers after opening wedge osteotomy was almost double (OR 4.8) that of closing wedge osteotomies (OR 2.9).

CONCLUSION

Smoking increases the risk of non-union during elective knee osteotomy surgery. Our findings also suggest that smokers have a better chance of achieving union with closing wedge osteotomy compared to open wedge osteotomy.

Total knee arthroplasty post-high tibial osteotomy, results of an early experience from a North African arthroplasty unit, and a comprehensive review of the literature

PURPOSE

To report an early experience after converting HTO to TKA by reporting the incidence of functional, radiological, and complications in a single surgeon case series from a North African specialized arthroplasty unit.

METHODS

Between 2010 and 2020, 33 knees in 31 patients (two bilateral) were operated upon, 24 females and seven males, had a mean age of 65 ± 4.5 years; 17 (51.5%) knees had medial wedge opening (WMO), while 16 (48.5%) had lateral wedge closure (LWC) osteotomies. The mean time from HTO to TKA was 8.1 ± 3.3 years. A posterior stabilized (PS) implant was used in 31 (93.9%), while in 2 (6.1%), a varus-valgus constrained (VVC) implant was used. A tibial stem was needed in 13 (39.4%) knees. The functional assessment was performed according to the Knee Society Scoring System (KSS). The radiographic assessment included the anatomical femorotibial angle (aFTA) for alignment, the medial proximal tibial angle (MPTA), and the tibial slope (TS).

RESULTS

After a mean follow-up of 4.3 ± 1.1 years, the KSS knee and function sub-scores improved from a preoperative mean of 41 ± 8.9 (26 to 57) and 37.7 ± 9.2 (25 to 55) points to 91.3 ± 3.8 (81 to 94) and 85.5 ± 5 (80 to 95) points at the last follow-up, respectively (P < 0.05). The preoperative knee flexion improved from a mean of 84.5° ± 15.9 (55 to 110) to 110.6° ± 9.3 (95 to 125) (P < 0.05). The aFTA improved from a preoperative mean of 182.2° ± 10.3 (164 to 205) to a postoperative mean of 186° ± 2.6 (179 to 190) (P < 0.05). The MPTA changed from a preoperative mean of 88.4° ± 6.7 (77 to 102) to a postoperative (tibial component alignment) mean of 90° ± 1.7 (85 to 94) (P < 0.05). The mean preoperative TS changed from 80.9° ± 7.3 (68 to 96) to a mean postoperative of 86.9° ± 1.3 (83 to 89) (P < 0.05). Non-progressive radiolucent lines were detected at the tibial component in four (12%) knees. Complications were reported in seven (21.2%) knees; no revision was needed in any knee.

CONCLUSIONS

The authors' early experience showed improved functional and radiological outcomes; however, the complication incidence was relatively high, but no knees required revision. A longer follow-up is mandatory to prove the consistency of the results.

Double-level torsional osteotomy a treatment for the 'inwardly pointing knee' syndrome

INTRODUCTION

A 'inwardly pointing knee' syndrome is a combined torsional deformity with increased femoral internal and tibial external torsion. After clinical and radiological verification of the torsional deformity and unsuccessful conservative therapy approach, a combined (double level) torsional osteotomy of femur and tibia might be the appropriate treatment. Here, we present the diagnostic algorithms, treatment, and outcome of combined torsional osteotomies of femur and tibia. The aim of the study is to show that patients treated with the procedure achieve patellofemoral stability and pain relief or reduction.

MATERIAL AND METHODS

Twenty torsional osteotomies performed on 18 patients were included. Nine patients had experienced patellar dislocation in 11 joints before. All patients were suffering from anterior knee pain. All patients underwent a clinical and radiographical evaluation, including a torsion angle CT scan. Pre- and post-operatively multiple commonly approved scores (Lysholm Score, Tegner Activity score, Kujala Score, VAS and Japanese Knee Society score) were acquired.

RESULTS

In 18 patients we performed 20 double-level torsional osteotomies. 9 patients suffered from patellar dislocations in 11 knee joints prior to surgery. All patients were suffering from anterior knee pain. Of these 7 patients achieved a stable joint after surgery without further patellar dislocations. All achieved more knee stability and experienced less patellar luxation then before surgery. The mean duration of follow-up was 59 months (range 9-173 months). The mean VAS was significantly reduced by 3.75 points (SD 2.09, p value 0.0002) from 5.50 points (SD 2.73, range 0-9) before surgery to 1.75 points (SD 1.67, range 0-5) after surgery. The Lysholm score increased significantly by mean of 27.6 (SD 17.55, p value 0.0001) from mean 62.45 (SD 22.71, range 22-100) before surgery to mean 90.05 (SD 10.18, range 66-100) after surgery. The Kujala Score did improve significantly in average by 25.20 points (SD 13.61, p value 0.00012) from mean 62.9 (SD 16.24, range 35-95) to mean 93.2 (SD 9.20, range 66-100). The Tegner activity score did increase significantly by 1.2 points (SD 1.47, p value 0.004) in average from mean 2.65 (SD 1.11, range 1-5) to mean 3.85 (SD 1.42, range 1-6). The Japanese knee score did increase significantly by 19.15 in average (SD 11.95, p value 0.0001) from mean 74.05 (SD 14.63, range 33-95) to mean 93.05 (SD 10.18, range 68-100).

CONCLUSION

This is the first publication reporting about simultaneous double-level torsional osteotomies in a comparatively high number of patients. In addition, this is the first publication assessing the patient collective afterwards with objectifying clinical outcome scores. The results show that double-level torsional osteotomy is an effective treatment for patients with patellar dislocation or subluxation associated to torsional deformities of femur and tibia. Furthermore, we introduce a diagnostic algorithm for 'inwardly pointing knee' syndrome.

LEVEL OF EVIDENCE

Level IV.

Smoking and the patient with a complex lower limb injury

Smoking is known to increase the risk of peri-operative complications in Orthoplastic surgery by impairing bone and wound healing. The effects of nicotine replacement therapies (NRTs) and electronic cigarettes (e-cigarettes) has been less well established. Previous reviews have examined the relationship between smoking and bone and wound healing separately. This review provides surgeons with a comprehensive and contemporaneous account of how smoking in all forms interacts with all aspects of complex lower limb trauma. We provide a guide for surgeons to refer to during the consent process to enable them to tailor information towards smokers in such a way that the patient may understand the risks involved with their surgical treatment. We update the literature with recently discovered methods of monitoring and treating the troublesome complications that occur more commonly in smokers effected by trauma.

A hinge position distal to the adductor tubercle minimizes the risk of hinge fractures in lateral open wedge distal femoral osteotomy

PURPOSE

To evaluate the incidence and morphology of medial cortical hinge fractures in lateral open wedge distal femoral osteotomy (LOW-DFO) and to determine a safe zone for the position of the osteotomy hinge to minimize the risk of hinge fractures.

METHODS

Consecutive patients who underwent LOW-DFO for symptomatic valgus malalignment were screened for eligibility for this retrospective observational cohort study. Demographical and surgical data were collected. The incidence and morphology of medial cortical hinge fractures were evaluated on standard postoperative anterior-posterior knee radiographs. Comprehensive measurements evaluating the osteotomy gap and the position of the osteotomy hinge were taken. Additionally, each osteotomy hinge was assigned to a corresponding sector of a proposed five-sector grid of the distal medial femur.

RESULTS

A total of 100 patients (60% female) with a mean age of 31 ± 13 years were included. The overall incidence of medial cortical hinge fractures was 46% and three distinct fracture types were identified. The most frequently observed fracture type was extension of the osteotomy gap (76%), followed by a proximal (20%) and distal (4%) course of the fracture line in relation to the hinge. Group comparison (hinge fracture vs. no hinge fracture) showed statistically significant higher values for the height of the osteotomy gap (p = 0.001), the wedge angle (p = 0.036), and the vertical distance between the hinge and the proximal margin of the adductor tubercle (AT; p = 0.002) in the hinge fracture group. Furthermore, a significantly lower horizontal distance between the hinge and the medial cortical bone (p = 0.036) was observed in the hinge fracture group. A statistically significant higher incidence of medial cortical hinge fractures was observed when the position of the osteotomy hinge was proximal compared to distal to the proximal margin of the AT (53% vs. 27%; p = 0.023).

CONCLUSION

Medial cortical hinge fractures in LOW-DFO are a common finding with three distinct fracture types. To minimize the risk of medial cortical hinge fractures, it is recommended to aim for a position of the osteotomy hinge at the level of or distal to the proximal margin of the adductor tubercle.

LEVEL OF EVIDENCE

Prognostic study; Level III.

Two-year clinical results of a novel load redistribution device for the treatment of medial knee OA

PURPOSE

A potential method to relieve the pain from medial osteoarthritis of the knee is to offload the medial compartment. The Latella^™ Knee Implant is a novel device designed to offload the medial compartment. The objective of the Cotera-1 study was to evaluate the preliminary safety and feasibility of the Latella implant to treat patients with medial OA of the knee, by a 2-year follow-up of a prospective multicenter feasibility study (Cotera-1) performed in the Netherlands and UK METHODS: In this first-in-man study, 11 participants received the Latella implant and were followed for 2 years, documenting physician assessment, Patient-Reported Outcome (PRO) scoring (KOOS, IKDC, Kujala, SF-36); Patient Global Assessment (PGA), radiographic analysis and MRI analysis, complications, reoperation rate and hip-knee-ankle axis.

RESULTS

The Latella Knee Implant system proved to be well tolerated and demonstrated a low-risk safety profile up to 24 months post-treatment. A responder analysis was performed of the subjects who still had the Latella implanted at 24-month time point (n = 9). Based on a MCID of eight for KOOS pain sub-scale, 78% of the subjects at the 24 month time point would be considered as responders. Similarly, based on improvement in the medial knee pain compared to baseline using the NRS scale of 1-10, 89% of the subjects at the 24-month time point would be considered as responders. Two patients were revised during follow-up: one for arthrofibrosis and one converted to TKA for progression of OA.

CONCLUSIONS

The early clinical experience with the Latella Knee Implant in this pilot feasibility study has been encouraging. It appears to be a safe implant with possible effect on medial OA. Additional studies need to be performed to assess the safety and efficacy of the procedure in a larger patient population.

LEVEL OF EVIDENCE

II.

[Retrograde bone transport nail in a posttraumatic femoral bone defect]

We report the case of a 28-year-old man who developed nonunion with complex deformity after treatment of a distal femoral fracture with an antegrade femoral nail. The resulting deformity was as follows: 10° varus, 21° external torsion, 1.8 cm of foreshortening and translation malalignment. After resection of the pseudarthrosis, a retrograde segmental transport nail was implanted. During the same surgical procedure, acute internal torsion, valgization and lengthening correction was performed. The segment transport was performed using a magnetically driven internal transport nail. Seven months after surgery, bony consolidation of the distraction section and the docking site was observed. The leg axis was straight and the rotational movement ranges of the knee and hip corresponded the dimensions of the contralateral side.

Three-Dimensional Volumetric Changes After Socket Augmentation with Deproteinized Bovine Bone and Collagen Matrix

PURPOSE

Socket augmentation decreases the magnitude of alveolar ridge resorption, but the literature is limited in respect to quantifying soft tissue remodeling. The aim of this study was to determine the volumetric and linear dimensional changes at the buccal surface for both hard and soft tissues after socket augmentation treated with a xenogeneic collagen matrix in combination with bone grafting.

MATERIALS AND METHODS

Twenty-four individuals indicated for tooth extraction were enrolled in this investigation. Each participant was randomly assigned to one of two groups: (1) deproteinized bovine bone + collagen plug, or (2) deproteinized bovine bone + xenogeneic collagen matrix. A cone beam computed tomography scan was taken prior to extraction and at 6 months postextraction. Intraoral scanning images were taken at baseline, 3 months, and 6 months postextraction. Hard and soft tissue analyses were performed to compare linear ridge remodeling and volumetric changes by noncontact reverse-engineering software.

RESULTS

Both groups showed bone and soft tissue remodeling. For hard tissue remodeling, there was no significant difference between the collagen plug and collagen matrix groups. For soft tissue remodeling, the collagen matrix group showed a reduced soft tissue loss compared with the collagen plug group. The volumetric analysis demonstrated that the mean buccal soft tissue volume loss for the collagen matrix group was 68.6 mm³ compared with 87.6 mm³ found in the collagen plug group (P = .009) over a 6-month period.

CONCLUSION

This clinical investigation provides early evidence of using the total tissue volume to compare soft and hard tissue remodeling after socket augmentation. The results of this study demonstrated that the use of a xenogeneic collagen matrix reduced the buccal soft tissue loss after tooth extraction, but additional studies are necessary to evaluate the clinical significance of soft tissue augmentation after tooth extraction.

A meta-analysis of total knee arthroplasty following high tibial osteotomy versus primary total knee arthroplasty

BACKGROUND

This study was performed to compare the clinical and radiographic outcomes of total knee arthroplasty (TKA) following high tibial osteotomy (HTO) versus primary TKA.

METHODS

Relevant trials were identified via a search of Ovid, PubMed and the Cochrane Central Register of Controlled Trials from inception to 10 January 2019. A meta-analysis was performed to compare postoperative outcomes between revising HTO to TKA (RHTO) and primary TKA (PTKA) with respect to Knee Society Score (KSS), 10-year survival rate, operative time, flexion and extension angle, infection rate and radiographic results.

RESULTS

Sixteen of 340 studies involving 103,552 adult patients (RHTO group, n = 3955; PTKA group, n = 99,597) were eligible for inclusion in the meta-analysis. Compared with primary TKA, revising HTO to TKA required longer operative time and had a higher infection rate (P < 0.05). The PTKA group had better flexion angle than the RHTO group (P < 0.05). There were no significant differences between the two groups in the KSS, extension angle, radiographic results and 10-year survival rate (P > 0.05).

CONCLUSION

Patients who undergo conversion of HTO to TKA have similar 10-year survival rate, KSS, extension angle and radiographic results as patients who undergo primary TKA. However, conversion of HTO to TKA required longer operative time and had a higher infection rate than performing primary TKA. Moreover, conversion of HTO to TKA is associated with poorer flexion angle than primary TKA.