Surgical treatment of inferior pole fractures of the patella: a systematic review

PURPOSE

This study aimed to comprehensively review the existing evidence concerning surgical treatment of inferior pole fractures of the patella and to report the outcomes and complications of different fixation techniques.

METHOD

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches of PubMed, Scopus, and Web of Science were conducted in March 2023. Studies were screened against predecided inclusion and exclusion criteria. The extracted data included fracture characteristics, surgical techniques, and radiographic and functional outcomes. The Methodological Index for Non-Randomized Studies (MINORS) quality assessment tool was used to assess the eligible literature. The primary outcome was postoperative range of motion of different surgical methods, and the secondary outcomes were other clinical results and complications.

RESULTS

A total of 42 studies satisfied all the inclusion criteria and were deemed suitable for review. Fourteen case-control studies and 28 case series were selected, for a total of 1382 patients with a mean age of 51.0 years (range = 11-90). The follow-up period ranged from 6 to 300 months. The surgical techniques were categorized based on the device used as follows: (1) rigid fixation device; (2) tensile fixation device; (3) mixed device; and (4) extra-patella device.

CONCLUSION

Regarding the outcomes following surgical treatment of inferior pole fractures of the patella, the postoperative range of motion (ROM) of each technique ranged from 120° to 135°, with the exception of that involving the patellotibial wire which had poorer outcomes. The lowest functional score was also found in those using the patellotibial wire. Complications after surgery are rare, but approximately half of the patients required additional surgery for implant removal, particularly those whose initial surgery involved rigid fixation devices. It's worth noting that bony fragment excision is no longer recommended, and the combined use of multiple surgical devices is now more common.

Evaluation of the anatomical factors affecting the success of retrograde intrarenal surgery for isolated lower pole kidney stones

Studies which examine the factors affecting success rate in kidney stones located in the lower pole as well as the effects of infundibulopelvic angle (IPA) and infundibular length (IL) have been conducted with a small number of patients. We aimed to evaluate the cut-off points of IPA and IL parameters that effect the success of retrograde intrarenal surgery (RIRS) for isolated lower pole kidney stones. This retrospective study includes 168 patients who underwent primary RIRS due to isolated lower pole kidney stones in our clinic between January 2013 and May 2020. Pre-operative demographic data, medical history, physical examination, surgery duration as well as the post-operative hospitalization time of patients specifics were obtained. According to pre-operative computed tomography (CT), stone size, stone burden, stone density, number of stones (single and multiple), stone laterality, congenital kidney abnormality, the presence of solitary kidney, parameters of IPA and IL were measured and both included in the study. All patients were divided into two groups as the successful group and the unsuccessful group according to their post-operative success. These two groups were compared in terms of pre and post-operative data. Stone burden, IPA < 42.65°, and IL > 27.5 mm were specified as the independent risk factors for success of RIRS procedure. The patients for whom RIRS procedure is planned for lower pole kidney stones, stone burden, IPA, and IL should be taken into consideration to be able to predict success and it should be kept in mind that additional treatment may be required.

Reinforcement of the Triple D score with simple addition of the intrarenal location for the prediction of the stone-free rate after shockwave lithotripsy for renal stones 10-20 mm in diameter

PURPOSE

We investigated the clinical efficacy of the Triple D score (TrD-S) on stone-free rate (SFR) prediction following shockwave lithotripsy (SWL) for renal stones 10-20 mm in diameter and modified the scoring system to improve outcome prediction.

METHODS

We retrospectively examined clinical data from the medical records of 226 consecutive patients who underwent SWL for 10-20 mm kidney stones. The TrD-S was calculated according to the cutoffs of < 150 mm³ for stone volume, < 600 Hounsfield unit for stone density, and < 12 cm for skin-to-stone distance on computed tomography. The Quadruple D score was defined as the sum of the TrD-S and stone location (0/1 point for intrarenal stone distribution at lower/non-lower poles, respectively). Complete clearance 3 months after the final SWL was considered the stone-free status.

RESULTS

The residual group (n = 102) had significantly older age, larger stones, higher stone density, higher lower-pole stone incidence, and lower TrD-S than the stone-free group (n = 124). In the multivariate analysis, age, TrD-S, and non-lower-pole stones independently predicted the SFR. The TrD-Ss of 0, 1, 2, and 3 points showed SFRs of 40.0%, 51.9%, 73.0%, and 100.0%, respectively. The Quadruple D scores of 0, 1, 2, 3, and 4 points showed SFRs of 0.0%, 37.9%, 54.5%, 84.4%, and 100.0%, respectively, with better prediction accuracy than the TrD-S (p = 0.01).

CONCLUSIONS

The TrD-S is successfully validated for use in Japanese patients with 10-20-mm renal stones. Simple addition of the stone location to the TrD-S could reinforce SFR prediction after SWL.

A contemporary lower pole approach for complete staghorn calculi: outcomes and efficacy

PURPOSE

Percutaneous nephrolithotomy (PCNL) is the preferred surgical treatment for staghorn stones. Two approaches are commonly employed to gain access into the collecting system which consists of either an upper pole (UP) approach or lower pole (LP) approach. However, opinions vary on which approach offers the best access and outcome. In this study, we aim to challenge the traditional paradigm that staghorn stones are most effectively treated through a prone UP approach. We herein report our institutional experience using a prone LP access in PCNL for patients with complete staghorn stones.

METHODS

Data were prospectively collected over 3 years on 473 PCNL procedures, of which 76 patients had complete staghorn calculi (five or more calyces). Operative and peri-operative outcomes were analyzed to compare a modified LP approach with the more widely accepted UP approach.

RESULTS

A total of 59/76 (77.6%) patients had LP access. There was no difference in the ability of completing the surgery utilizing a single tract as opposed to multiple tracts (74.6% of LP patients vs. 76.5% of UP patients). Stone-free rates for LP and UP access were similar (74.5 versus 70.5%, respectively; p = 0.760. Complication rates were lower for LP access vs. UP access (3.4 vs. 23.5%, p = 0.02) with two pulmonary complications in the UP group. Overall median operative time was not significantly different between LP and UP access (112.0 vs. 126.0 min, p = 0.486).

CONCLUSIONS

Prone LP access demonstrated similar efficacy with decreased morbidity in patients with complete staghorn calculi compared to prone UP access.

The value of three-dimensional helical computed tomography for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones

Objective

The aim of our study was to determine if there is any advantage of three-dimensional helical computed tomography (3D-HCT) over intravenous urogram (IVU) for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones.

Methods

From June 2012 to January 2014, a total of 52 cases of lower pole renal stones underwent retrograde intrarenal surgery (RIRS) in our center. All patients underwent a preoperative IVU and three-dimensional helical computed tomography urography (3D-CTU) program to define the collecting system anatomy, manly concerning the following lower pole features; infundibu-lopelvic angle (IPA), infundibular length (IL), and infundibular width (IW). The examinations were performed in the same center of reference with a standardized method and with 3D-HCT Siemens Somaton Plus equipment. The measurements were performed by the same researcher, using a ruler and a square.

Results

Based on clinical threshold difference of the anatomic factors on an IVU image to compare the difference between an IVU image and a 3D-CT image of 52 patients, the IPA was <30° when measured on intravenous pyelography (IVP) for 21 patients. We found that with the IPA of <30° measured with IVP only 19% (4/21) were correctly classified in the same size category using 3D-HCT, whereas 81% (17/21) were upgraded to 40–50° on 3D-CT. This difference was significant between IVP and 3D-HCT.

Conclusions

3D-HCT has advantages over IVU when analyzing the morphometric and the morphological features of kidney lower pole spatial anatomy for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones.

Management of lower pole renal stones: the devil is in the details

Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) are highly effective treatment options for lower pole stones up to 2 cm. Selecting the best treatment modality represents a controversial area in urology, because each treatment methods have their own advantages and disadvantages. Donaldson and co-workers have recently published a very comprehensive review and meta-analysis to compare the benefits and harms of SWL, RIRS and PNL techniques.

Extracorporeal shockwave lithotripsy vs. percutaneous nephrolithotomy vs. flexible ureterorenoscopy for lower-pole stones

Objectives

To review previous reports and discuss current trends in extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and ureterorenoscopy (URS). ESWL was recommended as the first-line treatment for small and intermediate-sized stones in the lower pole, while it is the standard treatment for large stones. However, the stone clearance rate after ESWL seems to be lower than that of stones in other locations. This seems to result from a lower rate of fragment passage, due to anatomical factors.

Methods

Reports on urinary stone disease were reviewed, assessing only publications in peer-reviewed, Medline-listed journals in the English language (publication years 1990–2011).

Results

Recent experience with flexible URS (fURS) for intrarenal stones showed that excellent stone-free rates can be achieved. With increasing experience and technically improved equipment, fURS has become an alternative to ESWL for small and intermediate-sized renal stones. Furthermore, several authors reported successful retrograde treatment for large renal stones, proposing fURS as an alternative to PCNL. However, the major drawbacks are long operating times and commonly, staged procedures, which is why PCNL remains the method of choice for such stones.

Conclusions

Considering the currents trends and evidence, the 2012 update of the European Association of Urology Guidelines on Urolithiasis has upgraded the endourological treatment of kidney stones. Individual factors such as body habitus, renal anatomy, costs and patient preference must be considered.